Fuel

Energy Conversion; Fossil Fuels; Attractive Sources of Energy; Alternative to Fossil Fuels and Their Relative Advantages and Disadvantages Energy Conversion; Fossil Fuels; Attractive Sources of Energy; Alternative to Fossil Fuels and Their Relative Advantages and Disadvantages Introduction Energy comes in different forms and different terms distinguished one form from another. Potential energy is called the energy that possessed by an object due to its position. Kinetic energy is called the energy possessed by an object due to its motion. Energy is neither created nor destroyed; it only converted from one form to another.

Conversion energy from one form to another Potential energy can be converted into kinetic energy and vice versa. The classic example of this intra-conversion is a pendulum. Throughout a swing of a pendulum the total amount of energy (potential plus kinetic) is constant. When the pendulum reaches its highest point at the end of the movement, all its energy becomes potential energy. As it begins, a downward swing gains kinetic energy and loses potential energy. At the lowest point of its trajectory all its energy is converted into kinetic energy.

As its proceeds to swing to its highest point it loses kinetic energy and gains potential energy. At the highest point all of its energy is once again a potential energy. All of the different forms of energy are intro-convertible. For example: electrical energy is converted into light energy in the bulb, into mechanical energy in the washing machines, and into thermal energy in an oven. “The chemical energy of a molecule of glucose is converted to mechanical energy in our muscles” (James B. Seaborne, 2002). The majority of our technological devises are converters of different forms of energy.

What does it mean by fossil fuel? “In a sense, the fossil fuels are a one-time gift that lifted us up from subsistence agriculture and should eventually lead us to a future based on renewable resources” Kenneth Deffeyes, 2001). The energy we use today is mainly from fossil fuels. The fossil fuels include gas, oil, coal, uranium, etc. All of these fuels are created over millions of years from the decay of plants and animals under high temperature and pressure. These resources are located in the bowels of the Earth. The formation of fossil fuels continues to this day, but their use is much faster than formation.

For this reason, fossil fuels are considered non-renewable because their resources can be exhausted in the near future. Coal provides about 35% of the world’s energy. It has been applied before other fossil fuels. “Most of the coal deposits formed about 286-360 million years ago” (James B. Seaborne, 2002). The most important element in the composition of coal is carbon. The oldest and hardest rock anthracite coal contains about 98% carbon, and only 30% of lignite (age of less than 1 million years old). Oil accounts for about 40% of the world’s energy.

It was formed millions of years ago due to the expansions of plankton and small water animals. “Oil and natural gas are called hydrocarbons, because they consist of two elements, hydrogen and carbon” (Kuhn, Karl F. 1996). Petroleum products are widely used for cars, trucks and other machineries. Oil is used in agriculture, and also is an essential material for many other industries. Natural gas accounts for about 20% of the world’s energy. Gas is generated in the same manner as oil, and as a rule, is carried out in parallel with the production of oil. The main component of natural gas is methane.

According to current assumptions the total natural gas reserves on the Earth are about the same as the oil. Attractive sources of energy “I’d put my money on the sun and solar energy. What a source of power! I hope we don’t have to wait until oil and coal run out before we tackle that” (Thomas Edison, 1931). There are natural sources of energy like Wind, Water, and Sun. Inasmuch these sources provide clean, safe, and nearly carbon-free energy they are considered attractive sources of energy. Our society is very advantageous to use these sources because they are renewable and therefore very stable.

For example, we are able to use the kinetic energy of wind and water. Electrical generators using turbines convert the energy into conventional electricity. Two different energy alternatives to fossil fuels; how they work; how they compare with fossil fuels, and their relative advantages and disadvantages Fossil fuels are a limited resource. In addition, “increasing amounts of fossil fuels such as oil, gas and coal leads to an increase in emissions of CO2” (Kuhn, Karl F. , 1996). This, in turn, causes global warming. Today, the power of water as a source of energy is used to produce electricity.

The modern hydropower plant includes dams and huge reservoirs that provide water pressure from a fall from a great height. Water wheels mounted on hydro-turbine in which the flow of water turns the rotor. Each turbine is connected to electric generator. The major advantage of hydroelectricity is the use of inexhaustible resources. Unlike fossil fuels, hydro-resources do not pollute the atmosphere. However, the flooding of large areas to create reservoirs harms the environment and destroys the ecological balance. Great expectations are associated with the use of nuclear power.

In a nuclear reactor, the heat produced in the splitting of an atom of a radioactive element, known as uranium-235. Emitted in the nuclear reaction, heat is used to produce steam turns a turbine to generate electricity. Compared to fossil fuels, nuclear energy has a number of advantages. It provides fuel economy: “a ton of U-235 gives us more energy than 12 million barrels of oil. It’s clean and does not pollute the atmosphere kind of energy” (Kuhn, Karl F. , 1996). However, there are drawbacks. Construction of the plant is expensive. There are hazardous radioactive waste generate during their operation.

As a result, the nuclear accident, like the one that occurred at Chernobyl in Ukraine in 1986, could be contaminated vast areas, causing serious illness and even death. After the Chernobyl disaster, some countries have decided to close down their nuclear power plants. Resources http://www. planetseed. com/relatedarticle/alternatives-fossil-fuels http://www. altenergy. org/nonrenewables/nonrenewables. html http://www. afdc. energy. gov/fuels/index. html http://www. fueleconomy. gov/feg/bifueltech. shtml http://www2. epa. gov/science-and-technology/ecosystems#aquatic

Why We should save natural resources because if we don’t, life will die out Have you ever wondered what would happen to the earth if we used all of the natural resources? Is it a possibility that this would happen in the near future? Well, at the current rate of resources being used it might happen. Renewable resources can Be used more than once. On the other hand non-renewable resources cannot be restored after being used once it’s used. Additionally non-renewable resources are in limited supply and be used once.

Examples of these resources are Coal,oil and natural Gasses, they are known to be fossil fuels; They take millions of years to form. They have to be mined or drilled from deposits deep within the earth. And the Reason we should save them is because if we don’t what will we have left for example if we use too much paper we will end up cutting down all the tree’s on earth causing the CO2 level’s to go to high and kill us all. That is why my family save all paper we use and double side our work. The Future of our economy lies in how much we use natural resources.

And according to the Political Economy of Natural Resources “The Development and taking of Resources leads to wars among countries and within countries”(the Political Economy of Natural Resources) And if natural resources Cost more money guess who suffers? The people do, Such as if we use up all our oil the price for a car and it’s maintenance would be very high. And Gail Tverberg believes “If the price of oil goes up the price of everything goes up” Natural resources don’t only affect the economy but the environment too. Natural resources are found throughout nature.

So when we use it up the environment suffers to most. Without forests in certain areas will never have forests again. So by cutting down trees you are basically abusing the earth. And a source states “That forested area are decreasing 1% every year” so basically in about 100 years we will die unless we stop cutting down trees and planting more of them. And half the world’s forest has already been cut down so without the trees what will stop the the soil erosion will permanently destroy the land and if that land is destroyed.

And if the land is destroyed what will trap the Carbon dioxide or give oxygen. So if we take the natural resources, the bionetwork = earth abuse = no life after some amount of years. The world’s population has grown over the years, and because of this, more resources are needed. and as more people are born there is fossil fuels used because we need to heat more people’s heating bills and electricity. So the More people born then dead in a day can make the years the earth have less.

And i have a some reasons why hydrogen should be our fuel until we can plant enough trees for soil erosion to go away and to get some more natural resources Reasons= It is colorless and odorless it is not a fossil fuel With the right technology using hydrogen, the sun and the wind we could get enough energy to power the whole US in 1 year. and after all the whole us is been powered stably we could store that energy and within 10 year we could have power to power the whole planet for at least 2 full years and all of the power is coming from renewable sources.

And 90% of it is produced from natural gas after we make it pure it will be able to power almost everything including automobile, heat, electricity, and water Clean burning fuel It does’t emit greenhouse gasses which ruins the ozone layer Although Nonrenewable can be made from water (which has 2 part hydrogen and 1 part oxygen) and the sun. It can be made without mining from a limited supply It can be replenished through a natural processes it is the simplest element with only one proton and one eletron.

|Document ID: |Standard Operating Procedures’ Title: |Print Date: | |ORIGIN-CA2 |CASSAVA PROCESSING |08/07/2012 | |Revision: |Written By: |Date Prepared: | |01 |Ayodele E. J.

AJAYI, General Manager Operations |08/07/2012 | |Effective Date: |Reviewed By: |Date Reviewed: | |mm/dd/yyyy | |mm/dd/yyyy | | |Approved By: |Date Approved: | | | |mm/dd/yyyy | |Applicable Standard: None | |Company: ORIGIN Group of Companies Limited Vegefresh Foods Limited, Nigeria. | |In Africa, cassava is mostly used for human consumption in various forms ranging from boiling the fresh tuber to processing it into cassava flour. |[pic] Cassava starch in the making: freshly harvested roots roll | |along a conveyor belt at a processing plant in Brazil | | | |[pic] | | | | | | | | | |Cassava Starch. | | | | |

Policy: It is a policy of this Company to provide Standard Operating Procedure documents that contain instructions on how to perform assigned tasks. Purpose: The purpose of this document is to ensure that routine tasks on the farm are performed safely, qualitatively and in compliance with applicable regulations. Below are some of the ways, this Standard Operating Procedure could have direct or indirect positive impact on ORIGIN Group’s Agric business performance: a) People need consistency to achieve top performance. This SOP will reduce system variation, which is the enemy of production efficiency and quality control. b) This SOP will facilitate training.

Having complete step-by-step instructions helps trainers ensure that nothing is missed and provides a reference resource for trainees. c) This SOP can be an excellent reference document on how a task is done and what are the expectations from employees filling in on the jobs they do not perform on a regular basis. d) This SOP can help in conducting performance evaluations. They provide a common understanding for what needs to be done and shared expectations for how tasks are completed. e) Employees can coach and support each other if there is documentation available on exactly how various tasks must be done and everyone knows what their co-workers are supposed to be doing.

This can also help generate a more cooperative team approach to getting all the daily tasks done correctly, everyday. f) This SOP encourages regular evaluation of work activity and continuous improvement in how things are done. Scope: This SOP is written for Production Managers, Lab Technician, Factory workers and Sales Distributors. The specific tasks within “Cassava Processing” are covered. This SOP does not cover the Cassava Production, Harvesting and Marketing. Responsibilities: The Production Managers, Lab Technician, Factory workers and Sales Distributors should be responsible for coordinating and implementing the Cassava Processing Factory and product sales tasks.

The Production Manager is responsible for training and managing the Factory Workers, Supervisors, Lab Techs etc; Production Manager should support the objectives policies of the Company and provide input to further development of SOPs. He/she would be responsible for planning, organizing, supervising and managing the activities of the entire factory and the routine maintenance of all factory equipment. Factory Workers are expected to discharge their duties efficiently and in compliance with the Standard Operating Procedures, work manual and equipment manual provided. The Standard Operating Procedures 1. 0 Cassava processing Cassava processing aims at increasing the quality and storability of cassava tubers.

This enhances the ability of the farmers to develop additional products, such as baking products out of cassava flour. It further ensures reduction or total elimination of undesirable toxic constituents in cassava so that it is suitable for human consumption. A. Producing Cassava Flour and Chips: I. Using low-cyanide varieties – Freshly harvested cassava is peeled using a knife. The peeled cassava is then washed and sliced into smaller pieces (chips). These are then dried on a raised platform under direct sun for about 2 days or specially-made driers, until moisture content of about 8 to 10 % is reached. Properly dried chips become tough to break, but crumble into flour when hit with a hard item like a hammer.

The drying process should be done continuously and the drying chips should not be exposed again to water to avoid molding. The chips may then be ground or milled into flour; dried chips store better than flour. II. Using high-cyanide varieties – Freshly uprooted cassava are peeled and sliced into smaller pieces (chips). The sliced chips are then dried in the sun for about 3 days to about 14 % moisture content. The chips are then soaked in water for 8 hours, and dried again to a moisture content of about 8 %. B. Producing Gari – Fermented cassava dough: Gari is a creamy-white or yellow dried cassava product, common in West Africa. It is prepared by peeling the outside of the tuber skin and washed. The washed tubers are then grated using a grater.

It is then packed in bags with holes to drain off the liquid and left to ferment for 1 to 5 days, depending on the preferred flavour. The fermented material is then pressed to let out the extra water leaving a cassava cake. The remaining cake is broken loose and spread on frying metal trays above a fire. The particles are fried until crisp and dry, about 10 % moisture content. The gari is then cooled, sieved and packed for sale or storage. C. Cassava Starch extraction After washing and peeling, roots are grated to release starch granules. The “starch milk” – water containing suspended granules then, separated from the pulp, after which the granules are separated from the water by sedimentation or in a centrifuge.

At that point, the starch requires solar or artificial drying to remove moisture before being milled, sieved and packed. In artisanal production systems, daily starch output ranges from 50 to 60 kg of starch per worker, while semi-mechanized processing can yield up to 10 tonnes a day. In modern, fully mechanized starch extraction plants, daily output is as high as 150 tonnes. Cassava Processing Equipment I. Traditional cassava processing does not require sophisticated equipment. Processing cassava into gari requires equipment such as grater, presser and fryer. The traditional cassava grater is made of flattened kerosene tin or iron sheet perforated with nails and fastened onto a wooden board with handles.

Grating is done by rubbing the peeled roots against the rough perforated surface of the iron sheet which tears off the peeled cassava root flesh into mash. In recent years, various attempts have been made to improve graters. Graters which are belt-driven from a static 5 HP Lister type engine have been developed and are being extensively used in Nigeria. Its capacity to grate cassava is about one ton of fresh peeled roots per hour. II. For draining excess liquid from the grated pulp the sacks containing the grated pulpy mass are slowly pressed down using a 30-ton hydraulic jack press with wooden platforms, before sieving and roasting into gari. Stones are used in traditional processing to press out the excess moisture from the grated pulp.

Tied wooden frames are used for this purpose in places where stones are not available. Pans made from iron or earthen pots are used for roasting the fermented pulp. Fuel wood is the mad or source of energy for boiling, roasting, steaming and frying. Fuel wood may not be easily and cheaply obtained in the future because of rapid deforestation. III. Slight changes in the equipment used in processing can help to save fuel and lessen the discomfort, health hazard, and drudgery for the operating women. The economic success of any future commercial development of cassava processing would depend upon the adaptability of each processing stage to mechanization.

However, the first step to take for improvement of cassava technologies should be to improve or modify the simple processing equipment or systems presently used, rather than to change entirely to new, sophisticated, and expensive equipment. Storage of cassava processed products Processing, particularly drying and roasting, increases shelf life of cassava products. Good storage depends on the moisture content of the products and temperature and relative humidity of the storage environment. The moisture content of gari for safe storage is belong 12. 7%. When temperature and relative humidity are above 27°C and 70% respectively, gari goes bad (Igbeka 1987). The type of bag used for packing also affects shelf life depending on the ability of the material to maintain safe product moisture levels.

Jute and hessian bags are recommended in dry cool environments because they allow good ventilation (Igbeka 1987). When gari, dried pulp and flour are well dried and properly packed, they can be stored without loss of quality for over one year. Dried cassava balls (“kumkum”) can be stored for up to 2 years (Numfor end Ay 1987). “Chickwangue”, “Myondo” and “Bobolo” can be preserved for up to 1 week but they can be kept for several more days when recooked. Cassava leaves as vegetable I. Cassava shoots of 30 cm length (measured from the apex) are harvested from the plants. The hard petioles are removed and the blades and young petioles are pounded with a pestle in a mortar.

A variation of this process involves blanching the leaves before pounding. The resulting pulp is then boded for about 30-60 minutes. In some countries, the first boiled water is decanted and replaced. Pepper, palm-oil and other aromatic ingredients are added. The mixture is then boiled for 30 minutes (Numfor and Ay 1987). Unlike the roots that are essentially carbohydrate, cassava leaves are a good source of protein and vitamins which can provide a valuable supplement to predominantly starchy diets. Cassava leaves are rich in protein, calcium, iron and vitamins, comparing favorably with other green vegetables generally regarded as good protein sources.

The amino acid composition of cassava leaves shows that, except for methionine, the essential amino acid values in cassava exceed those of the FAO reference protein (Lancaster and Brooks 1983). II. The total essential amino acid content for cassava leaf protein is similar to that found in hen’s egg and is greater than that in oat and rice grain, soybean seed, and spinach leaf (Yeoh and Chew 1976). While the vitamin content of the leaves is high, the processing techniques for preparing the leaves for consumption can lead to huge losses. For example, the prolonged boiling involved in making African soups or stews, results in considerable loss of vitamin C. III. Cassava leaves form a significant part of the diets in many countries in Africa.

They are used as one of the preferred vegetables in most cassava growing countries, particularly in Zaire, Congo, Gabon, Central African Republic, Angola, Sierra Leone, and Liberia. The cassava leaves prepared as vegetable are called “sakasaka” or “pondu” in Zaire, Congo, Central African Republic and Sudan, “Kizaka” in Angola, “Mathapa” in Mozambique, “Chigwada” in Malawi, “Chombo” or “Ngwada” in Zambia, “Gweri” in Cameroon, “Kisanby” in Tanzania, “Cassada leaves” in Sierra Leone, “Banankou boulou nan” in Mali, “Mafe haako bantare” in Guinea, and “Isombe” in Rwanda. They are mostly served as a sauce which is eaten with chickwangue, fufu, and boiled cassava. Revision History: Revision |Date |Description of changes |Requested By | |01 |08/07/2012 |Initial Release | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | References: http://www. fao. org/index_en. htm http://www. fao. org/ag/agp/agpc/gcds/ [pic]

The Global Cassava Partnership, a consortium formed – under the auspices of the FAO-facilitated Global Cassava Development Strategy – by international organizations, including FAO, CIAT, IFAD and IITA, national research institutions, NGOs and private partners. International Institute of Tropical Agriculture (IITA). Starting a Cassava Farm – IPM Field Guide for Extensions Agents. 2008; International Institute of Tropical Agriculture (IITA). Disease Control in Cassava Farms. IPM Field Guide for Extension Agents; International Institute of Tropical Agriculture (IITA). Weed Control in Cassava Farms. 2000. IPM Field Guide for Extension Agents; In-Service Training Trust (ISTT). Cassava Production Field Guide. 2008. NRDC Campus, Lusaka, Zambia. ———————– ORIGIN Group’s SOP: Confidential and Proprietary Page 6

AEROSPACE ENGINEERING SCHOOL OF MECHANICAL ENGINEERING AND DESIGN THE THERMODYNAMIC ANALYSIS AND PERFORMANCE CHARACTRISTICS OF A TURBOFAN JET ENGINE By J. E, Ibok 2011 Supervisor: Dr Lionel Ganippa ABSTRACT This work focuses on the performance analysis of a twin spool mixed flow turbofan engine. The main objective was to investigate the effects of using hydrogen, kerosene and natural gas fuel on the performance characteristics such as net thrust, specific fuel consumption and propulsive efficiency of the turbofan.

Another aim of this work was to introduce the concept of exergy and thermoeconomics analysis for twin spool mixed flow turbofan engine and show the components that contributes the most to the inefficiency of the engine. A generic simulation was carried out using Gas Turb 11 software to obtain reasonable analysis results that were verified with a real-time JT8D-15A turbofan engine. The parametric analysis was done for constant value of mass flow rate of fuel and constant turbine inlet temperature for all three fuels.

The result were rightfully obtained for these analysis cases and discussed accordingly. Brunel University Mechanical Engineering Academic Session: 2010/2011 Name of Student: Johnson Essien Ibok Supervisor:Dr Lionel Ganippa Title: The Performance Characteristics and Thermodynamics Exergy and Thermoeconomics analysis of a Twin Spool Mixed Flow Turbofan Engine Operating at 30,000ft at M0 0. using Kerosene, natural Gas and Hydrogen Fuel. Abstract: This work focuses on the performance analysis of a twin spool mixed flow turbofan engine. A generic simulation was carried out using Gas Turb 11 software to obtain reasonable analysis results that were verified with a real-time JT8D-15A turbofan engine. The parametric analysis was done for constant value of mass flow rate of fuel and constant turbine inlet temperature for all three fuels.

The result were rightfully obtained for these analysis cases and discussed accordingly. Objectives: The main aim of this work is to conduct the parametric cycle simulation of a twin spool mixed flow turbofan engine and investigate the performance characteristics of it. Another aim of this work is to show the effects of using hydrogen, Kerosene and natural gas fuel on the overall performance of the twin spool mixed flow turbofan engine.

Also, the purpose of this work is to introduce the use of the second law of thermodynamics analysis known as exergy and thermoeconomics in analysis the twin spool mixed flow turbofan engine Background/Applications: This work is applicable in so many ways when it comes to the overall performance optimization and feasibility analysis of a jet engine. This work relates to the aerospace and aviation industries since the turbofan engine is amongst the vast number of jet engine used in propulsion of aircrafts.

There is increasing pressure in the aviation industry to reduce pollution and depletion of energy resources while at the same time maintaining reasonable investment cost and high overall performance. Hence, this research was conducted in hopes of coming up with a new solution to this problem. Conclusions: The main conclusion drawn from the performance analysis is that hydrogen fuel produced the highest thrust level and the lowest specific fuel consumption between the three fuels for a constant mass flow rate of fuel.

Kerosene fuel generated thrust level can be increased if it is mixed with a small amount of hydrogen. The Exit jet velocity ratio remained constant despite the increasing bypass ratio for all three fuels at constant mass flow rate of fuel. Using the exergetic analysis showed that the combustion chamber and the mixer contributed the most to the inefficiency of the turbofan engine. The amount of exergy transferred into the turbofan engine by hydrogen was depleted in the smallest ratio compared to natural gas and kerosene for constant mass flow rate of fuel.

The thermoeconomics analysis showed that it is preferable to use local based cost evaluation to quantity specific thermoeconomics cost of thrust than the global method since the value was lower. Results: The results obtained from the simulation using Gas Turb 11 produced an error range of 0. 25% – 8. 5% when verified with the actual test data of the JT8D-15A turbofan engine. The results obtained for the analysis defined a reference design point at which the parametric analysis was conducted on. The analysis was done in three cases as shown clearly in the test matrix in table 1 below.

Analysis| Parameters being varied| Parameters Kept Constant| Performance Characteristics| case 1| * Bypass ratio * Turbine Inlet temperature| * HPC Pressure Ratio * LPC Pressure Ratio * Fan Pressure Ratio| * Velocity ratio * Fuel-Air-ratio * Turbine inlet temperature * Net thrust * Specific Fuel Consumption * Thermal efficiency * Propulsive efficiency| case 2| * Bypass Ratio * Three different fuelsmH2mCH4mC12H23| * Mass flow rate of fuel * HPC Pressure Ratio * LPC Pressure Ratio * Fan Pressure Ratio| | Case 3| * Bypass Ratio * Three different fuelsmH2mCH4mC12H23| * Turbine inlet temperature * HPC Pressure Ratio * LPC Pressure Ratio * Fan Pressure Ratio| | Table 1 The Test matrix of the Parametric Analysis. The exergy analysis was done for the parametric analysis of case 2 and case 3 where the exergy destruction rates, exergetic efficiency, exergy improvement potential rate and fuel depletion ratio were calculated. The distribution of these results throughout each component of the turbofan engine was represented with bar charts and Grassmann diagram. The thermoeconomics analysis was conducted for analysis case 2 using kerosene fuel.

The specific thermoeconomics cost of thrust was calculated using global and local based cost evaluation methods. ACKNOWLEDGEMENTS First of all, I would like to thank my parents for their financial support and encouragement because without them I would not be here and be able to do this work. I am deeply thankful to my supervisor, Dr Lionel Ganippa for believing in me and giving me the opportunity to work with him in this field of study. I am also thankful to him for giving the necessary guidance and advice and his enthusiasm and innovative ideas inspired me. Finally, I would like to thank Mr Joachim Kurzke for providing me with the necessary software needed for my dissertation. Table of Contents

Acknowledgements i Contents ii List of Notations and Subscripts iv List of Tables vi List of Figures vi Chapter 1: Introduction1 1. 1. Aims and Objectives2 1. 2. Computational Modeling3 Chapter 2: Jet Engines4 2. 1. Performance characteristics4 2. 1. 1. Thrust4 2. 1. 2. Thermal Efficiency5 2. 1. 3. Propulsive efficiency5 2. 1. 4. Overall efficiency6 2. 1. 5. Specific Fuel Consumption6 2. 2. Fuel and Propellants For Jet Engines7 Chapter 3: Turbofan Jet Engines ……………………………………………………………… …8 3. 1. Introduction 8 3. 2. Classification of Turbofan Engines9 3. 3. Major Components of a Turbofan Engine10 3. 3. 1. Diffuser10 3. 3. 2. Fan and Compressor11 3. 3. 3. Combustion Chamber12 3. 3. 4. Turbine13 3. 3. 5. Exhaust Nozzle14 3. 4.

Thermodynamic Process and Cycle of a Twin Spool Mixed Flow Turbofan Engine15 Chapter 4: Mathematical and Gas turb 11 Modeling of the turbofan Engine18 4. 1. Station Numbering and Assumptions18 4. 2. Design Point Cycle Simulation of the Turbofan Engine18 4. 3. Off-design Point Cycle Simulation of the Turbofan Engine21 4. 3. 1. Module/Component Matching 22 4. 3. 2. Off-Design Point Component Modeling22 Chapter 5: Methodology, Results and Discussions26 5. 1. General Relationship equations of the Major Parameters27 5. 2. Results and Discussions of Parametric cycle Analysis of Case 129 5. 3. Results and Discussions of Parametric Cycle Analysis of Case 235 5. 4.

Results and Discussions of Parametric Cycle Analysis of Case 343 Chapter 6: Exergy and Thermoeconomics Analysis of the Turbofan Engine49 6. 1. Exergy Analysis49 6. 1. 1. Exergy Analysis Modeling 50 6. 1. 2. Exergy and Energy Balance Equations of the Components58 6. 1. 3. General Relationships in Exergetic Analysis of the Turbofan Engine60 6. 1. 4. Results and Discussions61 6. 1. 5. Grassmann Diagram72 6. 2. Thermoeconomics Analysis74 6. 2. 1. Thermoeconomics Analysis Modelling74 6. 2. 2. Global Based Cost Evaluation76 6. 2. 3. Local Based Cost Evaluation77 6. 2. 4. Results and Discussion of the Thermoeconomics Analysis78 Chapter 7 Conclusions and Future Work80 Reference Appendix A Exergy Analysis Results Appendix B Thermoeconomics Analysis results

List of Notations and Units ?| Isentropic efficiency| ?| Total Pressure ratio| m| Mass Flow Rate (kg/s)| f| Fuel/Air Ratio| M| Mach Number| Pt| Total pressure (kPa)| Tt| Total Temperature (K)| NCV| Net Calorific Value (MJ/kg)| Ht| Total Enthalpy (kJ/kg)| V| Velocity (m/s)| ?| Bypass Ratio| T| Static Temperature (K)| P| Static Pressure (kPa)| N| Actual Spool Speed (RPM)| Nc| Corrected Spool Speed (RPM)| mc| Corrected Mass Flow Rate (kg/s)| R| Universal Gas Constant (kJ/kmolK)| ?0| Standard Chemical Exergy (kJ/kmol)| Ex| Exergy Rate (MW)| xi| Mole Fraction| cp| Specific Heat at Constant Pressure (kJ/kgK)| ?| Ratio of Chemical Exergy to NCV| ?| Exergetic Efficiency| | Fuel Depletion Ratio| W| Power Rate of Work done (MW)| List of Subscripts| | LPT| Low Pressure Turbine| HPT| High Pressure Turbine| CC| Combustion Chamber| HPC| High Pressure Compressor| LPC| Low Pressure Compressor| d| Diffuser| noz| Nozzle| mix| Mixer| dest| Destruction Rate| 0, ambFAR| Ambient conditionFuel-Air-Ratio| CH| Chemical| PH| Physical| KN| Kinetic| PN| Potential| IP| Exergy Improvement Potential Rate (MW)| CRF| Cost Recovery Factor| c| Specific Thermoeconomic Cost (MJ/kg)| STD| Standard Temperature and Pressure| TIT| Turbine Inlet Temperature| TSFC| Thrust Specific Fuel Consumption (g/kNs)| SFC| Specific Fuel Consumption| p| Propulsive| TH| Thermal|

O| Overall| T| Thrust| equip| Equipment| PEC| Capital Cost of Equipment| List of Tables Table 1 input parameters for Design Point Cycle Simulation on Gas Turb 1119 Table 2 Comparison table for the Actual Test Data and Simulated Data using gas Turb 1121 Table 3 Comparison Table for Actual Test Data and Simulated Off-Design Point data Using gas Turb 11. 25 Table 4 Equivalence Ratio of the three Fuels Combustion Processes………………………… 62 Table 5 Assumed Capital costs of Each Component of the Turbofan Engine. 75 Table 6 Flow of Specific Thermoeconomics Cost in all the Components 79 List of Figures Figure 1 Classification of Turbofan Engine9

Figure 2 Layout of Forward Fan Twin Spool Mixed Flow Turbofan16 Figure 3 T-S Diagram for the Forward Fan Twin Spool Mixed Flow Turbofan17 Figure 4 Design Point Cycle Simulation Algorithm Using Gas Turb 1120 Figure 5 Example of a Compressor Performance Map/Curve24 Figure 6 Effects of Varying Bypass Ratio at Constant Values of TIT on Fuel-Air-Ratio30 Figure 7 Effects of Varying Bypass Ratio at Constant Values of TIT on Exit Velocity Ratio30 Figure 8 Effects of Varying Bypass Ratio at Constant Values of TIT on LPT Exit Pressure Ratio31 Figure 9 Effects of Varying Bypass Ratio at Constant Values of TIT on Net Thrust32 Figure 10 Effects of Varying Bypass Ratio at Constant Values of TIT on Specific Fuel Consumption33 Figure 11 Effects of Varying Bypass Ratio at Constant Values of TIT on Propulsive Efficiency34 Figure 12 Effects of Varying Bypass Ratio t Constant Values of TIT on Thermal Efficiency35 Figure 13 T-S diagram of using Hydrogen Fuel when the bypass Ratio is increased36 Figure 14 Variation of Fuel-Air-Ratio with Bypass Ratio at Constant Fuel Flow Rate using three different Fuels37 Figure 15 Variation of TIT with Bypass Ratio at Constant Fuel Flow Rate using three different Fuels37 Figure 16 Variation of Exit Velocity Ratio with Bypass Ratio at Constant Fuel Flow Rate using three different Fuels38 Figure 17 Variation of LPT Exit Pressure Ratio with Bypass Ratio at Constant Fuel Flow Rate using three different Fuels39 Figure 18 Variation of Net Thrust with Bypass Ratio at Constant Fuel Flow Rate using three different Fuels40 Figure 19 Variation of Specific Fuel Consumption with Bypass Ratio at Constant Fuel Flow Rate using three different Fuels41 Figure 20 Variation of Thermal Efficiency with Bypass Ratio at Constant Fuel Flow Rate using three different Fuels42 Figure 21 Variation of Propulsive Efficiency with Bypass Ratio at Constant Fuel Flow Rate using three different Fuels43 Figure 22 Variation of Fuel-Air-Ratio with Bypass Ratio at Constant TIT using the three Different Fuels44 Figure 23 Variation of Exit Velocity Ratio with Bypass Ratio at Constant TIT using the three Different Fuels44 Figure 24 Variation of LPT Exit Pressure Ratio with Bypass Ratio at Constant TIT using the three Different Fuels45 Figure 25 Variation of Net Thrust with Bypass Ratio at Constant TIT using the three Different Fuels46 Figure 26 Variation of Specific Fuel Consumption with Bypass Ratio at Constant TIT using the three Different Fuels46 Figure 27 Variation of Propulsive Efficiency with Bypass Ratio at Constant TIT using the three Different Fuels47 Figure 28 Variation of Thermal Efficiency with Bypass Ratio at Constant TIT using the three Different Fuels48 Figure 29 Variation of Exergy Destruction Rate Using the three Fuels for Analysis Case 262 Figure 30 Variation of Exergy Destruction Rate Using the three Fuels for Analysis Case 364 Figure 31 Variation of Exergetic Efficiencies Using the three Fuels for Analysis Case 266 Figure 32 Variation of Exergetic Efficiencies Using the three Fuels for Analysis Case 367 Figure 33 Distribution of Exergy Improvement potential Rate Using the three Fuels for Analysis Case 268 Figure 34 Distribution of Exergy Improvement potential Rate Using the three Fuels for Analysis Case 369 Figure 35 variation of Fuel Depletion ratio using the Three Fuels for Analysis Case 270 Figure 36 variation of Fuel Depletion ratio using the Three Fuels for Analysis Case 371 Figure 37 Grassmann Diagram for the Exergetic analysis of Case 2 using kerosene Fuel for the Turbofan engine. 72 Chapter 1 Introduction Jet engines are complex thermodynamic systems that use a series of non-linear equation to define their thermodynamic processes and they operate under the principle of Brayton cycle.

Brayton cycle is a cycle that comprises of the compressor, combustor and turbine working as a unit. Additionally, the major parameters that dictate the operational conditions of the engine at any point during the process are the relative altitude and Mach number. Mach number is the ratio of the velocity of the jet engine to the speed of sound. Basically, the main purpose of this type of thermodynamic system in aerospace industry is to accelerate a jet of air and as a result, generate enough thrust needed for flight. In addition, the design of jet engines is dependent of what purpose it will be used for in order to derive its maximum performance.

For instance, in military application, jet engines are required to generate maximum thrust in minimum response time which consumes a lot of fuel whereas commercial jet engines are required to less noise generative, less fuel consuming and at the same time have high overall efficiency (El-sayed, 2008). There are certain factors that jet engine manufacturers take into consideration when designing jet engines which are the operating cost, engine noise, environmental emissions, fuel burn and overall efficiency. Accordingly, this has caused a global market competition for engine manufacturers like Rolls Royce, Pratt and Whitney, General Electric and CFM on who can produce the most efficient jet engines.

In fact, Pratt and Whitney Company is working on a geared turbofan jet engine that they believe will reduce fuel burn, produce lesser noise and emit less toxics while General Electric is coming up with simpler “ecore” jet engines that will be more fuel efficient than the current jet engines with as much as almost two fifths of current jet engines (Cassidy, 2008). Taking all that has been said into consideration, it can easily be asserted that by reducing the fuel consumption of the jet engine, the total temperature at the turbine blades will reduce thereby increasing the operating life and overall efficiency of the engine. Also, the total cost of the engine can be cut down. Indeed, Dr Pallan cited in (Ward, 2007) stated that reducing the fuel consumption by as little as 1% is highly longed after by engine manufacturers and this can result in very significant increase in the overall performance.

In a general point of view, it can be said that the maximum point of achievement for jet engine manufacturers would be to design an engine that consumes the minimum amount of work in the compressor unit while generating the maximum amount of work in the turbine unit at minimum fuel supply. The main purpose of this work is to analyse the thermodynamic processes and performance of a jet engine using a simulation tool, exergy and thermoeconomics concept. 1. 1. Aims and Objectives The main objective of this work is to carry out the thermodynamic analysis and show the performance characteristics of a turbofan jet engine. In this work, the vivid explanation of the thermodynamics processes and cycle of each component of the turbofan engine starting from the diffuser to the nozzle will be covered. Also, the first and second law of thermodynamics with other laws will be applied extensively throughout this work.

However, in the aspect of performance characteristics of the turbofan engine, a generic simulation will be carried out on a twin spool mixed flow turbofan engine. To relate this work to real life application, a JT8D-15A turbofan engine manufactured by Pratt and Whitney Company will be used as the twin spool mixed flow turbofan for the simulation using the original design data. Indeed, the simulation tool that will be used is GasTurb 11 which was designed by Joachim Kurke and for more details on how it works can be found in (Kurke, 2007). This work will use the reference design point of the twin spool mixed flow turbofan at sea level with maximum take-off thrust to obtain the operating point of 30,000ft at M0 0. using the off-design performance simulation which will serve as the operating design point for the analysis in this work since the engine will spend most of its time in the cruise phase between 30000ft to 38000ft. The purpose of carrying this generic simulation of the turbofan engine is to investigate the effects of varying bypass ratio and turbine inlet temperature (thermal limit parameter) on the performance characteristics of the turbofan engine. In other words, the parametric cycle studies of the turbofan engine. This investigation will be done for three different cases which case 1 will be studying the effects of varying bypass ratio and turbine inlet temperature on the performance characteristics of the turbofan engine when some of the design choices are kept constant.

The second case of study will be the comparison of the performance characteristics of the turbofan engine when three different fuels (kerosene, natural gas and Hydrogen) are used at the same mass flow rate using the same design point in case 1. Finally, the third case of study will be the comparison of the performance characteristics of the turbofan engine when the three fuels are undergoing the same combustion process that is constant turbine inlet temperature for the design point in case 1. This aspect of this analysis is very important owing to the growing problem of greenhouse effect and depletion of energy resources. In fact, statistics by the intergovernmental panel shows that aerospace industry is amongst one of the fast growing sources of greenhouse effect and that the emission of carbon dioxide will increase to five times what it is presently which is 3% (Symonds, 2005).

Based on this, using alternative fuels like hydrogen and natural gas can tend to reduce pollution and consumption of energy resources risk and this work aims to show how that can be achieved while the overall efficiency of the engine is still high. Another approach of analysis in this work will be the use of the second law of thermodynamics analysis also known as exergy and thermoeconomics. This aspect of analysis of the turbofan engine will be done for the parametric analysis of case 2 and case 3 in efforts to also compare the three fuels that are being considered and show which fuel will cause the turbofan engine components to be most inefficient or have the most irreversibility.

This analysis will be done by calculating the exergy relationships such as exergy transfer rates, exergy destruction rates, exergetic efficiencies, exergy improvement potential rates, and fuel depletion ratios. Furthermore, the exergy analysis will be represented in a Grassmann diagram for parametric analysis case 2 of study. However, as for the thermoeconomics analysis of the turbofan engine, only parametric analysis case 3 studies will be done for only kerosene fuel and this work will aim to show how to use concept of local and global evaluation of thermoeconomic cost. 1. 2. Computational Modelling It will be very expensive and time wasting to design and develop new aircraft engine whenever an optimization or analysis wants to be done.

In fact, Caoa Y, Jin, Meng and Fletcher (2005) stated that new ways should be developed to reduce aircraft engine design, maintenance and manufacturing cost in order to have effective worldwide market competition. Surprisingly, computer modelling is one approach of reducing manufacturing cost and time wasting. Computational modelling can simply be defined as the use of computer codes to replicate a typical system using some of its original data in order to analyse the system at varying conditions. The other side of the medallion shows simulation. There are many types of simulation tools normally used in simulating gas turbines such as Matlab/simulink, Modelica, Gas Turb 11, NPSS and many more. However, the simulation tool that will be adopted for the purpose of this dissertation is Gas Turb 11 designed by Joachim Kurzke.

Gas Turb 11 is a language oriented program with a command prompt that calculates the output data without using block diagrams or graphical interface. It is user friendly in a sense that it is easy to find the tools library and to substitute data in for simulation. The Gas Turb 11 is specifically designed for simulation of all kinds of gas turbines starting from power generators to jet engines. Gas Turb 11 usually carries out two types of analysis which are the on design cycle point simulation and off-design cycle point simulation. Engine design point cycle simulation involves the study of comparing gas turbines of different geometry. This cycle design point must be defined before any other simulation can be done.

On the other hand, off-design performance cycle point simulation involves the study of the behaviour of a gas turbine with known geometry. This cycle outlines the performance characteristics of each component such as performance maps, Overall efficiency. The type of simulation that will be done in this dissertation will involve the off-design and design point cycle. Chapter 2 Jet Engines 2. 1. Performance Parameter of Jet Engines 2. 2. 1. Thrust Thrust is the way of quantifying the ability of a jet engine to effectively utilise the energy added to it in order to propel or push itself forward in the opposite direction of the exiting jet in the exhaust nozzle.

In other words, it is the reactive force to the force imparted by the exiting jet in the nozzle in accordance to Isaac Newton’s third law of motion. It is the most important parameter that has to be obtained for any jet engine and it depends heavily on the ingested mass of air, exiting velocity and pressure, the area of the nozzle, the flight velocity and ambient conditions. In fact, the mathematical expression for thrust which incorporates these factors is shown below as. Thrust=meVe-m0V0+Pe-P0Ae Where, e=the exit conditions at the exhaust nozzle, 0=ambient conditions at the inlet me=m0+mfuel Momentum Thrust=meVe; This is the thrust obtained from the reaction of the hot exhaust gases high velocity.

Momentum Drag= m0V0 ; This the friction or drag force caused by the high velocity ingestion of air mass at the inlet. Pressure Thrust=Pe-P0Ae; This force is generated as a result of the higher exit static pressure compared to the ambient pressure which pushes back at the engine. Gross Thrust=meVe+Pe-P0Ae; It is the maximum obtainable positive thrust a jet engine can have when the drag forces are ignored. Special Cases of Thrust Take-off Thrust It is the thrust a jet engine can generate with its own power at static or low power setting which means the momentum drag component of thrust is ignored and the power of the engine at this point is equivalent to zero.

This can be used to explain why the thrust of an engine at take-off condition is usually higher than at cruise condition since there is no momentum drag and effects of varying ambient condition. This only applies to turbojet, turbofan, and turboprop jet engines but when it comes to ramjet and scramjet, the air flow has to be accelerated by a booster system before it can start producing a positive take-off thrust. Pressure Thrust Component This is the thrust generated as a result of the static pressures of the exiting jet and ambient environment. In ideal cases where the nozzle has perfectly expanded the jet exit pressure to that of the ambient condition, the pressure thrust component will disappear which this case is not possible in reality.

However, if the nozzle is choked which indicates that the ambient pressure is lower than the exit pressure of the jet, the pressure thrust component will have a positive effect on the net thrust. Also, if the nozzle tends to over expand the jet because of low energy addition to the jet and the exit pressure is lower than the ambient pressure, the pressure thrust component will have a negative effect on net thrust. 2. 2. 2. Thermal efficiency It is simply the measure at which energy in the engine system is converted. In other words, it is the measure at which total energy supplied to the engine system as heat transfer is converted to kinetic energy.

In another way, it can easily be said to be the ratio of the power generated in the engine airflow to the rate at which energy is supplied in the fuel. ?TH=Power Generated in the Engine AirflowRate of Energy Supplied in the Fuel =12? meVe2-12? m0V02mfuel? NCV 2. 2. 3. Propulsive efficiency It is a measure at which kinetic energy possessed by air as it passes through the engine is converted into power of the propulsion of the engine. In mathematical terms, it is simply known as the ratio of thrust power to the power generated in the engine airflow. ?p=Thrust PowerPower Generated in the Engine Airflow = T? V012? meVe2-12? m0V02 2. 2. 4. Overall Efficiency

As the name overall depicts, it is the resultant efficiency of a jet engine can have which is simply the product of the thermal and propulsive efficiencies. In mathematical terms, it is represented as shown below. ?O=? TH?? p =12? meVe2-12? m0V02mfuel? NCV? T? V012? meVe2-12? m0V02 =T? V0mfuel? NCV 2. 2. 5. Specific Fuel Consumption Specific fuel consumption as any other performance characteristics is a ratio and surprisingly it has a major effect on the economics of the aircraft as it is used to determine the aircrafts flight ticket costs. Specific fuel consumption has different expressions depending on what type of jet engine it is. For instance, in ramjet, turbojet and turbofan jet engines, it is the measure of the fuel mass flow rate to the thrust force generated.

Also, it is sometimes called the thrust specific fuel consumption (TSFC). TSFC=mfT However, in turbopropeller jet engines, it is the ratio of the fuel mass flow rate to the power generated in the engine shaft by the turbomachinery. It is sometimes referred to as the brake-specific fuel consumption (BSFC). TFSC=mfSP 2. 2. Fuel and Propellants for Jet Engines Fuels can implicitly be defined as substances used to add heat energy to a system through combustion or other processes. Fuels are mostly hydrocarbons like kerosene, diesel, petrol, alcohol, paraffin and butane and can also be in the form of individually free reactive molecular substances like hydrogen or chemical composites like natural gas, coal, wood.

The gaseous state substances used as fuels such as hydrogen, and natural gas (94% methane and 6% ethane) are usually made into a cryogenic state as in liquefied at very low temperature because of their low boiling point. It can easily be asserted by anyone that the only purpose that fuels have in jet engines is to add energy but little do they know that the purposes grows as the speed of the aircraft increases. For instance, Kerrebrock (2002) stated that supersonic aircrafts which attains very high stagnation temperature that can create destabilization to the airframe structure, engine component and organic substances like lubricants, uses its fuel as a coolant to this parts or components.

The energy added by the fuel burned per unit mass of air flow is called the heating value of the fuel and it is a very crucial parameter to be defined before any combustion process analysis is done on a jet engine since it shows how complete the combustion process is through efficiency. The heating value can either be said to be higher or lower depending on if the water product of combustion is a vapour or a liquid. Since the combustion process in jet engine produces vaporised water, the lower heating value of the fuel is used. The most frequently used fuels for jet engines are kerosene jet A1, A2, JP10 and many more but diesel can also be used. The disadvantages of these fuels are their inevitable emission of toxic substances that contribute to greenhouse effect and their risk of depletion.

Accordingly, this has been the driving force for the use of alternative fuels such as cryogenic hydrogen and natural gas which is believed will reduce toxic emissions. Besides, hydrogen is a carbon-free energy carrier and possesses almost no risk of toxic emission since most of its combustion product will be water Chiesa and Laozza (2005). Chapter 3 Turbofan Jet Engine 3. 1. Introduction Between 1936 and the next decade when turbofan engines were invented, people showed little or no interest in them as they described them to be a complicated version of a turbojet engine. However, in 1956, the benefits of turbofan engines started to be noticed as major companies like Rolls-Royce and General Electric began manufacturing them.

Since then, it is been one of the most used jet engine for commercial purposes because of its low fuel consumption and less noise production. In fact, it has been concluded to be the most reliable jet engine ever manufactured El –Sayed (2008). The turbofan jet engine gas generator unit comprises of a fan unit, compressor section, combustion chamber and turbine unit. Fundamentally, a turbofan jet engine operates as a result of the compressors pressuring air and supplying it afterwards for further processing. The majority of the pressurised air is bypassed around the core of the engine through a duct to be mixed or exhausted whereas the rest of it flows into the main engine core where it combusts with the fuel in the combustion chamber.

The hot expanded gas products from the combustion process passes through the turbine thereby rotating the turbine as it leaves the engine. Consequently, the rotating turbine spins the engine spool which in turn rotates the other turbo machinery in the engine. This causes the front fan to pressurise more and more air into the engine for the process to start all over again in continuous state. The turbofan engine is believed to be the perfect combination of the turboprop and turbojet engine and as a result, its advantages are usually compared to that of the turboprop and turbojet. In fact, Kerrebrock (1992) said that turbofan engine provides a better way of improving the propulsive efficiency of a basic turbojet.

It is asserted that at low power setting, low altitude condition and low speed, the turbofan engine is more fuel efficient and has better performance than a turbojet engine. Unlike turboprop engine where vibration occurs in the propeller blades at relative low velocities, the fan in the turbofan engine can attain high relative velocities of Mach 0. 9 before vibration occurs. Also, since the fan in turbofan engines has many blades, it is more stable than the single propeller so even if the vibration velocity is reached, the vibration will not destabilize the airflow because the vibrations are almost negligible. Since the flow into the diffuser of the turbofan is usually subsonic, there very slim chances of shock waves being developed at the entrance. 3. 2. Classification of Turbofan Engines

There are various types of turbofan engine ranging from high and low bypass ratio, afterburning and non-afterburning, mixed and unmixed flow with multi-spool, after fan and geared or ungeared. The classification of the various types of turbofan engines is shown below in figure 1. Nonetheless, the type of turbofan engine that would be used for the purpose of this dissertation is a forward fan two spool mixed flow turbofan engine. This type of turbofan engine was chosen because it is the compromise of a simple and complex turbofan engine. This is said because it comprises of almost all the classes of a turbofan which are low bypass ratio, forward fan with mixed flow, twin spool with ungeared fan.

Moreover, because of the mixed flow introduced, it produces additional thrust in the hot nozzle compared to the high bypass and it can also permit the addition of afterburner which produces a lot of thrust while consuming a lot of fuel which makes it suitable for military application which shows little worry on fuel consumption. In essence, carrying out a study on this type of turbofan engine will be of great relevance to the military air force sector especially if new research is discovered. TURBOFAN ENGINES Low Bypass Ratio Aft Fan Forward Fan Nonafterburning Afterburning High Bypass Ratio Geared Fan Single Spool Short Duct Ungeared Fan Two Spool Mixed Fan and Core Flow Unmixed Flow Long Duct Three Spool

Figure 1 Classification of Turbofan Jet Engines (El-sayed, 2008) 3. 3. Major Components of Turbofan Engine 3. 4. 1. Diffuser or Inlet Diffuser is the first component that air encounters as it flows into the engine. Basically, the purpose of a diffuser is to suck in air smoothly into the engine, reduce the velocity of the air, increase the static pressure of the air and finally, supply the air in a uniform flow to the compressor. Given the fact that overall performance of an engine is highly dependent on the pressure supplied to the burner, it is necessary to design a diffuser that incurs the minimum amount of pressure loss.

To demonstrate this, Flack (2005) stated that if the diffuser incurs a large total pressure loss, the total pressure in the burner will be reduced by the compressor total pressure ratio time this loss. In other words, a small pressure drop in the diffuser can translate into a significant drop in the total pressure supplied to the burner. Another point taken into consideration when designing a diffuser is the angle because if the angle is too big, there will be tendency of eddy flow generation due to early separation. The major causes of pressure losses in the diffuser are as follows. First, losses due to generation of shock waves outside the diffuser and it majorly occur in supersonic diffusers.

Secondly, the loss due to the unfavourable or adverse pressure gradient of the diffuser geometry which makes the flow separate a lot earlier and generates eddies. This separation causes a convergent area which makes the velocity not to be reduced by much. Due to the separation, the wall shear deteriorates the static pressure even further. Further analysis done by El-Sayed (2008), describes ways of accounting for this losses like using Fanno line flow and combined area and friction. Thermodynamic Process Equation In this analysis, the loss due to heat transfer is negligible so the process can be adiabatic. The initial kinetic energy is used to raise the static pressure p0 to the total pressure ? =pt2pt0 (inlet pressure recovery) efficiency ? d=IdealReal=ht2s-h0ht2-h0 assuming the gas is ideal and the specific heat at constant pressure is constant efficiency ? d=Tt2s-T0Tt2-T0 simplifying the equation given that ht0=ht2=ht2s and Tt2=Tt0and pt2s=pt2 TtT0=1+? -12M02 and TtT0=ptp0? -1? pt2p0=1+ ? d? -12M02?? -1 3. 4. 2. Fan And Compressors Compressor is a very crucial component for the operation of an engine in the sense that it prepares the air for the combustion process in the burner. The main purpose of a compressor as the first rotating component is to use its rotating blades to add kinetic energy to the air and later translate it into total pressure increase.

There are basically two types of compressors which are the centrifugal and the axial compressor. Firstly, centrifugal compressor as the name implies changes the direction of an axial airflow to a radial outflow of the air. It was the early compressors adapted in jet engines. It comprises of three main parts which are the impellers, the diffusers and the compressor manifold. The purpose of the impeller is to change the direction of the flow from axial to radial and at the same time increases its static pressure. The diffuser slows down the airflow and further increase the static pressure as it is supplied axially by the compressor manifold to the combustion chamber.

The centrifugal compressor is advantageous because the cost of manufacturing it is low compared to axial compressor and as a result is suitable for small engines like turboshafts and turboprops. It is also advantageous because the pressure ratios at single stage are higher than that of the axial compressor. The centrifugal compressor has the tendency of attaining low flow rates and as a result is ideally suitable for helicopters and small aircrafts which require low flow rates. On the other hand, the centrifugal compressor cannot attain high pressure ratio and so it is not suitable when high peak efficiency is required. It incurs a lot of losses due to the change in direction. Secondly, an axial compressor is the most reliable type of compressor and is usually applied when higher pressure ratios of up to 40:1 are required.

An axial compressor does not change the axial flow direction of the air but increases the total pressure. Indeed, an axial compressor comprises of three major components which are the rotor with blades, stator can and the inlet guide vane. A stage is a combination of a stator and a rotor. The assembly of the full rotor blade and stator can form the number of stages in a compressor and the greater the number of stages, the higher the total pressure ratio. In this arrangement, the air flows into the inlet guide vane and then into the rotor and stator assembly where compression starts. Also, the length of the rotor and stator reduces along the whole unit which signifies a reduction in volume which induces the increase in pressure.

A fan or low pressure compressor is a type of axial compressor but the only differences are that the blades are longer, the total pressure ratio is lower than the typical compressor and the number of stages is usually 1 or 2. The main purpose of creating a fan is to compress more air and to create a bypass air which can be used to generate addition thrust or used for mixing process. Fan Equation Process Given that, isentropic efficiency ? fan= Ideal CycleActual cycle=ht3s-ht2ht3-ht2 Since the specific heat is constant, the equation deduces to ? fan=Tt3s-Tt2Tt3-Tt2 Simplifying the equation whenpt3s=pt3, Tt3sTt2=pt3pt2? -1? , ? fan=pt3pt2 and ? fan=Tt3Tt2 ? fan=? fan? -1? -1? fan-1 Bypass Ratio=msma where ms is the bypass flow rate and ma is the engine core flow rate.

For the high pressure compressor, the equations remain the same as that of the fan except the changes in station numbering and the bypass ratio. 3. 4. 3. Combustion Chamber/ Burner The combustion chamber as the Brayton cycle implies is the only source of heat energy addition to the system. Accordingly, the combustion chamber causes very significant increase in the temperature of the air which results in the air gaining enormous internal energy. This energy gained is extracted to be used to power the turbine while the rest is used to create highly accelerated gases from the nozzle. There are three types of combustor namely; the can combustor, the annular combustor and the cannular combustor.

The main considerations when designing a combustion chamber is to ensure that the combustion process is complete with no fuel waste, the combustor should have long life materials because any failure can lead to engine explosion. The other consideration is that the air must be heated enough above the ignition fuel temperature in order to ensure stoichiometric combustion. Equations of the Combustion Chamber In the real process of the combustor, total and static pressure drops and the temperature also drop. The major causes of pressure losses are the high level of irreversibility or non-isentropic process and viscous effects in the burner. The burner pressure ratio ? =pt5pt4Burner temperature ratio ? b=Tt5Tt4 Since no work is done only heat transfer, the efficiency of the burner is analysed using the heating value NCV of the fuel used. Thus, efficiency ? b=heat addedHeating value of fuel=ma+mfht5-maht4NCVmf Given that f=mfma, ? b= 1+fht5- ht4NCVf Equivalence Ratio of combustion It is the ratio of the actual fuel to air ratio of the combustion process to the stoichiometric fuel to air ratio. This ratio produces a means of classifying the combustion process to show whether it is a lean, rich or stoichiometric combustion. The mathematical expression for this is as shown below ? =Actual FARStiochiometric FAR <1 Lean combustion process ?=1 Stiochiometric combustion process ?>1 Rich combustion process 3. 4. 4. Turbine Turbine can simply be said to be the antonym of a compressor. In response, a turbine extracts molecular kinetic energy from the air and uses it to drive the turbo machineries which results in the pressure and temperature of the air to drop. If truth be told, Flack (2005) asserted that the turbine uses 70% to 80% of the total energy gained by the air in the combustion chamber to drive the turbo machineries while the remaining 20% to 30% is used to generate thrust in the nozzle.

Since the geometry of a turbine have favourable pressure gradient unlike the compressor which is adverse, the efficiency of the turbine is usually very high. Since the turbine is the opposite of the compressor, it has exactly the same configuration of rotor and stator but the volume increase across it which induces the pressure drop. One major problem faced when design a turbine is the deterioration of the blades due to high inlet temperature from the combustion chamber. Based on this, (Song et al. 2002) demonstrated that General Electric uses about 16. 8% of the compressor air to cool the turbine blades of GE 7f engine. Turbine Equation Analysis Given that, Turbine efficiency ? T=ActualIdeal=ht6-ht5ht6s-ht5 T=Tt6-Tt5Tt6s-Tt5 Simplifying the equation given that pt6s=pt6 Tt6sTt5=pt6pt5? -1? ?T=pt6pt5 ? T=Tt6Tt5 ?T=? T-1? T? -1? -1 3. 4. 5. Exhaust Nozzle The nozzle is the final component of the jet engine that the air passes through. The main purposes of the nozzle is to add extra acceleration to the high velocity exiting air, reduces its total pressure to that of ambient condition and finally generate sufficient thrust. There are two conditions that occur in the exit of the nozzle depending on the ambient pressure. The first condition is termed under-expansion which occurs when the ambient pressure is less than the exit pressure of the gases.

The result of this is that the exit velocity will be lower than it normally is and this makes the momentum component of thrust to be lower than ideal. On the other hand, it will create a positive thrust component for the pressure terms. The second case termed as overexpansion which occurs when the ambient pressure is greater than the exit pressure of the gases. Consequentially, the opposite of what happens in the under-expansion condition occurs where the pressure term is lower and the momentum is higher. Nozzle efficiency ? n=ActualIdeal=ht8-h9ht8-h9s=Tt8-T9Tt8-T9s for constant specific heat Using the steady state energy equation and balancing it out, U9=2ht8-h9 . When specific heat is constant U9=2cpTt8-T9 p9pt8=T9sTt8? -1? T9Tt8=11+? -12M92 p9pt8=11+? -12M92-1+ ? n ? n 3. 4.

Thermodynamic Process and Cycle of Twin Spool Mixed Flow Turbofan Engine Before any explanation is done from Figure 2, the blue arrows represent the incoming air into the diffuser and the red represent the air flow into the core of the engine while the black arrow represent the bypass air flow through the fan. Finally, the brown arrow represents the air flow after the bypass air and the core air flow have mixed. Based on the arrangement of the turbofan engine in figure 2, it can be seen that air at ambient condition is sucked into the diffuser where the air velocity is reduced and some of its kinetic energy is used to increase the static pressure to the total pressure. The air exiting the diffuser enters the fan or low pressure compressor where it is compressed. Indeed, the molecules of the air gains kinetic and internal energy by colliding rapidly with one another and as a result increase the enthalpy and static pressure.

Also, in the fan, some of the compressed air is bypassed through a duct to be used for the mixing process later while the rest of the air enters into the high pressure compressor of the engine core. In the high pressure compressor, the air is further compressed where the enthalpy and pressure increases as it is released into the combustion chamber. Also, in the high pressure compressor, some of the air mass flow rate is bled out to be used to cool the turbine blades and for air conditioning in the aircraft. In the combustion chamber, the incoming fuel reacts with the air in an oxidation process at constant pressure where the by-product gases gain molecular kinetic energy thereby increasing the enthalpy.

This high temperature gases escapes into the high pressure turbine where it is expanded and the gases lose some of their kinetic molecular energy as it enthalpy and static pressure reduces. In other words, it can be said that the molecular kinetic energy of the gases is being converted to mechanical work which is used to power the high pressure spool. Consequently, the gases enters into the low pressure turbine where it is further expanded to a lower pressure and enthalpy as their molecular kinetic energy is converted to mechanical work to power the low pressure spool. These gases escaping from the low pressure turbine enters the mixing zone or mixer after it has lost most of its total enthalpy and mixes with the bypassed cold air from the duct to further reduce its enthalpy as that of the cold air increases.

In other words, the cold air absorbs some of the heat energy from the hot gases until they both attain equilibrium enthalpy. The mixture of the cold air and hot gases both escape at the same equilibrium enthalpy and pressure through the nozzle where their velocity is increased and the pressure is reduced considerably to that of the ambient condition. Furthermore, the exhausted high velocity gases is used to produced thrust for propulsion according to Newton’s third law of motion (In every action, there is equal and opposite reaction). 2 4. 5 6 4 13 0 HPC DIFFUSER FAN/LPC HPT LPT NOZZLE COMBUSTION CHAMBER 2. 5 3 5 8 16 BYPASS DUCT HP Spool LP Spool MIXING ZONE

Figure 2 Layout of a Forward Fan Twin Spool Mixed Flow Turbofan Engine P0 P3 P4. 5 P5 P8 P6 P2. 5 P2 P13 P4 ENTROPY (S)(kJ/kg) TEMPERATURE (K) Figure 3 T-S Diagrams for the Forward Fan Twin Spool Mixed Flow Turbofan Engine Chapter 4 Mathematical and Gas Turb 11 Modelling of the Engine 4. 1. Station Numbering and Assumptions Station numbering is a very crucial step that has to be taken when analysis of any thermodynamic system involving many processes is to be done. Moreover, station numbering contributes immensely to showing how the properties of one process relate to another and how the interaction between these processes derives the functional relationship of the thermodynamic system.

Returning to the work in hand, the station numbering system that has been adopted for this work on a JT8D-15A turbofan engine is in accordance with the Aerospace Recommended Practice (ARP) and it is shown in figure 2. Assumptions The following assumption were made based on Mattingly (2002) and Kurzke (2007) in order to perform the modelling as listed below * The air flow through the engine is assumed to be steady and one dimensional * The fan and the low pressure Compressor are driven by the low pressure turbine * The overall engine is assumed to have no bleeds in mass flow or power off-take in turbine. * The nozzle of the engine is choked which means the exit pressure will be greater than the ambient pressure. The air is assumed to act as a half ideal gas where the specific heat and ratio is dependent on temperature only. * The areas of each station of the engine is assumed to be constant 4. 2. Design Point Cycle Analysis of the Turbofan Engine The off-design or performance cycle analysis cannot be done without the design point cycle being defined. The design point cycle in this analysis is obtained using exactly the same data used in the actual test analysis for a JT8D-15A turbofan engine operating at sea level with maximum take-off thrust as shown in (“JT8D Typical Temperature and Pressure”) and (“ICAO”). Some of the input parameters such as the isentropic efficiencies and pressure ratios from the actual test data had to be calculated.

Since not all the input parameters were given from the actual test data, some of the parameters like inlet corrected mass flow rate, diffuser pressure ratio and efficiency; mechanical spool efficiency had to be guessed in order to complete the analysis and the data are represented below in Table 1. With all the Input Parameter being specified as shown in table 1, the design point cycle simulation of the JT8D-15A turbofan Engine using the Gas Turb 11 software can then be performed. All the steps taken to model the mixed flow turbofan engine on Gas Turb 11 is clearly represented in the algorithm shown in figure 3 below. COMPONENT| INPUT PARAMETER| | DIFFUSER| Pressure Ratio (? d)| 1| | Inlet Corrected Mass Flow Rate (mc2)| 138. 618 kg/s| FAN| Pressure Ratio (? fan)| 2. 054| | Isentropic Efficiency (? fan)| 0. 78| | Bypass Ratio (? )| 1. 08| Low Pressure Compressor (LPC)| Pressure Ratio (? LPC)| 4. 7| | Isentropic Efficiency (? LPC)| 0. 88| | Nominal Low Pressure Shaft Speed (NLP)| 8160RPM| High Pressure Compressor (HPC)| Pressure Ratio (? HPC)| 3. 77| | Isentropic Efficiency (? HPC)| 0. 864| | Nominal Low Pressure Shaft Speed (NHP)| 11420RPM| Combustion Chamber (cc)| Pressure Ratio (? CC)| 0. 934| | Isentropic Efficiency (? CC)| 0. 99| | Burner Exit Temperature (TIT)| 1277. 15K| High Pressure Turbine (HPT)| Isentropic Efficiency (? HPT)| 0. 9| | HP Spool Mechanical efficiency (? m)| 1| Low Pressure Turbine (LPT)| Isentropic Efficiency (? LPT)| 0. 91| | LP Spool Mechanical efficiency (? m)| 1| Table 1 Input Parameters for the Design Point Cycle Simulation START

Specify all the input data gotten from the actual test data as shown in Table 1 Run the Gasturb 11 software and select mixed flow turbofan from the drag down Tab list. Set the scope to ‘More’, set the Calculation Mode as Design and click ‘Run’ Choose the Units to either Imperial or SI and Select the type of fuel from to drop down list to Kerosene, Natural Gas or Hydrogen Estimate the inlet Corrected mc2 Mass Flow rate to the FAN/LPC Choose ‘Single Cycle’ for ‘Select a Task ‘Option and click ‘Run’ Check if the Thrust, SFC, ? HPT, ? LPT and EPR are within (0-10) % of the actual test Experiment END YES NO Figure 4 Design Point Cycle Simulation Algorithm Using Gas Turb 11 Verification of the Design Point simulation Results

Since not all the input parameters were specified in the actual test data and some of them had to be guessed, it is without any doubt that errors are bound to generate in the simulation results using the Gas Turb 11 software. In order to ensure that the errors accumulated in the simulation were within range, the major output parameters obtained such as net thrust, fuel flow rate, Engine exit pressure ratio, etc were compared to the actual test data as shown in Table 2 and the error range was calculated to be between 0. 25% to 8. 5% which is within an acceptable range. PARAMETERS| ACTUAL TEST DATA| SIMULATED DATA USING GASTURB 11| Net Thrust| 69307. 74| 69320| Engine Exit Pressure Ratio P8P0| 2. 09| 2. 167|

Burner Fuel Flow| 1. 100843| 1. 09781| HPT pressure Ratio (? HPT)| 0. 415| 0. 449| LPT Pressure Ratio (? LPT)| 0. 3294| 0. 3514| HPT temperature Ratio (? HPT)| 0. 8097| 0. 8435| LPT temperature Ratio (? LPT)| 0. 7718| 0. 793| Table 2 Comparison Table for the Actual Test Data and Simulated Data Using GasTurb 11 4. 3. Off-Design Point Cycle Simulation of the Turbofan Engine The off-design or performance cycle simulation takes into account the concept of module matching of each component through performance maps. This cycle analysis enables the determination of different operating point of the engine at a given design point of the engine.

Considering the work in hand, the design point have been defined and verified for the JT8D-15A turbofan engine operating at sea level with maximum take-off thrust which means that different operating points of the engine can be defined with the concept of off-design module matching of the engine. Indeed, the off-design operating point that was considered for the parametric analysis in this work was 30,000ft at M0 0. 8 for the turbofan engine. The off-design modelling of the JT8D-15A engine for the operating point of 30,000ft at M0 0. 8 based on the reference design point defined earlier is clearly demonstrated as follows. The off-design performance cycle simulation may contain some errors because of the component performance maps that were used for the simulation. 4. 3. 1. Module/Component Matching This process only applies to the off-design performance cycle point of the engine.

It can simply be defined as the act of synchronising each component of a jet engine to coexist as a unit in order to derive the overall performance characteristics of the jet engine. Component matching involves the process closely studying the ramifications of the actual jet engine overall performance behaviour on the components major characteristics such as pressure ratio, temperature ratio, efficiency and spool speed. This process introduces the concept of empirically determined component performance maps that establishes the relationship between the thermodynamic properties and the geometry of the jet engine itself. 4. 3. 2. Off-Design Component Modelling Diffuser The diffuser was assumed to be adiabatic and the pressure ratio ? d=1 The Isentropic Efficiency was assumed to be 1 For Sea Level,

Pamb=101325pa , Tamb=288. 15K For 30,000ft and M0 0. 8, Tamb=288. 15-0. 0065? 9144 =288. 15-59. 436 =228. 71K Pamb=101325? Tamb288. 155. 2561 =30. 09kpa Tt1=228. 71? 1+? -12M02 =228. 71? 1+1. 4-12? 0. 82 =258K pt1p0=1+ ? d? -12M02?? -1 pt1=30. 09? 1+ 1? 1. 4-120. 821. 41. 4-1 pt1=45. 8674kPa pt1=pt2 Tt1=Tt2 Fan and Low Pressure Compressor The inlet corrected mass flow rate is estimated as 138. 618kg/s , As for the off design simulation using the component performance maps for the altitude of 30000ft and Mach no. 0. 8, the actual spool speeds and inlet mass flow rate are calculated based on the estimated inlet corrected mass flow rate as shown below.

Low and High pressure spool mechanical efficiency is assumed to be=1 HP spool Speed=11420RPM, LP spool Speed=8160RPM m2=Pt2PSTD? mc2Tt2TSTD =45. 878101. 325? 138. 618258288. 15 Actual Mass flow rate m2=66. 3323kg/s N=Tt2TSTD? NcLP=228. 71288. 15? 8160=7722 RPM The calculated actual mass flow rate and spool speed were used to evaluation the isentropic efficiency and the pressure ratio of the LPC for that operating condition from the compressor performance map. Figure 5 Example of a Compressor Performance Map/Curve The diagram above in figure 4 depicts a typical compressor performance map that was used for the off-design point analysis in this work.

It can be seen that the x-axis represents the inlet corrected mass flow rate mc2 into the compressor, the y-axis represents the compressor pressure, the red contour lines represents the isentropic efficiencies and the black curved lines represent the relative corrected spool speed. To add to that, the red dash line that ends the speed lines and efficiency lines represent the surge margin which is also known as the stall line that must be avoided since the flow will become unstable in that region. In this work, the inlet corrected mass flow rate and spool speed were calculated which were interpolated on the performance map to obtain the pressure ratio and the isentropic efficiency.

For instance, the yellow dot on the map represents a design point traced for a given pressure ratio, High Pressure Compressor The inlet corrected mass flow rate into the HPC mc2. 5=mc21+? mc2. 5=138. 6182. 08=66. 64kgs m2. 5=Pt2. 5PSTD? mc2. 5Tt2. 5TSTD N=Tt2. 5TSTD? NcHP The same equation used for the LPC is used to calculate the actual mass flow rate and spool speed which is used to evaluate the isentropic efficiency and pressure ratio when it is operating at an altitude of 30000ft at M0 =0. 8. Verification of the off-design modelling for 30000ft at Mo 0. 8 In order to verify the simulation result gotten for the operational design point of 30000ft at M0 0. , the actual test data results gotten from Mattingly, Heiser and Pratt (2002) for the same operating condition was compared. Due to the difficulties in obtaining a lot of output parameters for this operating point, the result will be verified with only the net thrust generated and the specific fuel consumption. Indeed, the error accumulated was 1. 71% for the net thrust and 0. 83% for the specific fuel consumption. PARAMETERS| ACTUAL TEST DATA| SIMULATED DATA USING GASTURB 11| Net Thrust (lb)| 4920| 4836| Specific Fuel Consumption(lb/lbh)| 0. 779| 0. 7855| Table 3 Comparison Table for the Actual Test Data and Simulated Off-design Data Using GasTurb 11 Chapter 5

Methodology, Results and Discussions Given that the design point of the JT8D-15A turbofan engine at sea level has been obtained and verified with the actual test data, the operating point of 30000ft at M0 0. 8 was simulated and obtained which now served as the design point for the analysis in this work. Moreover, the procedure taken to define this design point of 30000ft at M0 0. 8 of the JT8D-15A turbofan engine has been clearly stated earlier which gives the permission to conduct the parametric cycle study of the turbofan engine. The parametric cycle studies were done for three different cases for the operational design point of 30000ft at M0 0. of the JT8D-15A turbofan engine as explained as follows. 1. The first parametric analysis case 1 aim to create an understanding of the effects of varying major design parameters on the performance parameters of the turbofan engine when some of the design choices are kept constant. In other words, the bypass ratio and thermal limit parameter (turbine inlet temperature) were varied when the design choices such as the compressor pressure ratio, fan pressure ratio and isentropic efficiencies were kept constant in order to investigate their effects on the performance parameters such as the net thrust, specific fuel consumption, propulsive efficiency, thermal efficiency, and fuel-air-ratio.

Much interest is shown nowadays in using alternative fuels like hydrogen and Natural gas in efforts to reduce the cancer known as pollution and the risk of depletion of energy resources. Based on this, conducting a research that focuses of comparing different fuels consumption rate, their risk of pollution and their contribution to the performance of the engine will be really valuable. Based on this, a parametric analysis had to be done on the JT8D-15A turbofan engine using three different fuels which are the design point fuel kerosene, hydrogen and natural gas. Since the original design point of the JT8D-15A turbofan was obtained using kerosene fuel, the design points of using hydrogen and natural gas was obtained using the same design choices as that of kerosene.

Now that the design points of the JT8D-15A turbofan engine had been defined when using the three different fuels, it had given a go ahead to perform whatever parametric cycle studies of the turbofan engine using the three fuels. In order to compare the performance characteristics of the turbofan engine when it is using the three different fuels, different approaches had to be devised to compare them effectively on a rational basis which defines the last two parametric analysis cases as follows. 2. The second case of parametric analysis was that the fuel flow rate would be kept constant for the three fuels that would be used as the bypass ratio is varied with design choices remaining the same. 3.

The third case of study was to make the energy supply into the combustion chamber of the turbofan engine the sa

“The planet takes care of us, not we of it. ” One could say that the planet earth is a system, interacting with objects in space such as the sun and the moon. The mass and diameter of these objects, their distance from earth and the amount of heat they radiates makes the conditions on earth ideal for life to exist. Over the years, humans have begun to consume at a much faster rate than before. Yes, fossil fuels like coal, natural gas and oil are being used at a greedy rate, but the ground is busy making some more.

Yes, too many trees providing shade, oxygen, clean air and water, fruit and nuts are being cut down to produce wood products such as paper, furniture and housing, but it’s not like we’ve run out of oxygen… the world always seems to work itself out. A problem is detected, the loophole discovered, and our planet renovates and replenishes itself. The earth doesn’t need our help, and even if it did, I don’t think we are prepared to offer it. Humans are greedy little children, and we never had to grow up because Mother Nature was always there for us even when we are not there for her.

Saving the world is a grand gesture needs a large amount of energy and people, and it would never happen that all the people of the world come together with one goal, to save the planet. We don’t even know how to properly fend for ourselves, nor do we know how to keep peace with our neighbors, so how could we ever even attempt to take care of the biggest thing we know, our home, our planet, our earth, which had been standing tall as it still is, four and a half million years before mankind even existed?

This of course, is only one approach to a hugely controversial topic, and the other side says we must live green and “reduce, recycle and reuse”. I do believe a lot of people want to see that happen and admire the concept, but they are just too lazy to go through with it. Either way, here comes my question, if we were going to lend a hand and “take care” of our planet, would that truly be what we are doing?

Or is that phrase just a witty twist of words used as a facade to conceal our self-centered nature… Think about it, if we cease to reduce our carbon footprint and encourage global warming, say we melt the icecaps and increase the sea-level, ruin the soil with our chemicals and pollute every acre of the earth with our damned plastic bags to the point where the air is too dirty to breathe, the soil too tired to harvest on and the water too toxic to drink.

What happens? Mankind will die out, life as we know it will never be the same, but the planet? The earth will still be here, only we will not. So are we really trying to take care of the planet, or are we just taking care of ourselves? Is us trying to take care of the planet a selfless, humanitarian act or is it just more evidence to our self absorbed nature?

Small individual differences in our lifestyle can add up to large changes in society. There are many automobile companies exploring different types of energy supplies other than gasoline. Conduct research on these alternative fuel sources for automobiles. Discuss one alternative to gasoline for automobiles. Give some detailed background information on the automobile model that uses an alternative fuel source and please answer the following. •Would you consider buying one of these in the future?

Why or Why Not? Yes, maybe. If I had the money for one. A dedicated natural-gas vehicle, like the Civic Natural Gas, runs exclusively on clean-burning natural gas. This guarantees 100% alternative-fuel use. Some other natural-gas vehicles use a “bi-fuel” system that doesn’t offer the same economic and low-emissions benefits that a dedicated system offers. A bi-fuel vehicle has two different fuel tanks—one containing traditional gasoline, and the other utilizing an alternative fuel such as natural gas. ttp://automobiles. honda. com/civic-natural-gas/faq. aspx •How many gallons of gas would you save annually if you bought one of these vehicles? Weight-saving technologies, improved aerodynamics and engine modifications result in a new Civic Natural Gas with an impressive EPA rating of 27/38/31 miles per gallon (gasoline-gallon equivalent)[1]. The recent engine and transmission changes have another upside: an increased range of over 10 percent, up to 190 miles. 1] 27 city/38 hwy/31 combined miles per gallon (gasoline-gallon equivalent). Based on 2012 EPA mileage estimates. Use for comparison purposes only. Do not compare to models before 2008. Your actual mileage will vary depending on how you drive and maintain your vehicle. Performance Features http://automobiles. honda. com/civic-natural-gas/performance. aspx •Why do you think there are not more of these vehicles in use? For one they cost to much. The price for one of these are $26,305

The global environment has been afflicted to a considerable extent by the conventional combustion engines of the vehicles, creating certain problems of global interest like exhaust emission, global warming and increased dependence on fossil fuel. (Paul Nieuwenhuis, Peter Wells, 2003)

It has been estimated that fossil fuels are a limited resource. Nissan has always played a key role in automotive industry and foreseen that mobility is an inevitable part of economic development of any country. Nissan has contributed his share by harnessing the technological strengths that has accumulated over many years of its dedication and ever-changing discoveries.

The basic charm in the philosophy of fuel cell vehicle is in its environment friendliness. It is expected to play an evermore important role as a clean energy vehicle. Main feature of fuel cell vehicle is that electrical energy is obtained by the chemical reaction of hydrogen and water. In this reaction sole emission is water which is already the part of ecosystem means least or almost no pollution. The electrical energy obtained in this manner will be utilized to get it converted into mechanical driving force by a number of engineering processes. (Lloyd Dixon, Isaac Porche, Jonathan Kulick, 2002).

The Nissan FCV employs elements of a variety of technologies, including electric vehicle (EV), hybrid electric vehicle (HEV), and compressed natural gas vehicle (CNGV) technologies.

Nissan’s FCV applies technologies that have been developed in Nissan, such as lithium ion batteries and high voltage electric systems for electric vehicles, control technologies for hybrid vehicles and high pressure gas storage systems for CNGV. Nissan has been developing FCVs that endeavors to accomplish outstanding environmental and energy-saving capacity. (Geographical, 2003)

Nissan Canada Inc. (NCI) declared in February 2006, a program that will put its newest fuel cell-equipped vehicle to the test trial for analysis. The new seventy mega Pascal (MPa) high-pressure hydrogen-powered Nissan X-Trail FCV (fuel cell vehicle) was at home in Canada for testing, which will take place in the vicinity of the Greater Vancouver. The Nissan X-Trail FCV encloses a hydrogen fuel cylinder manufactured by Dynetek Industries Ltd. of Calgary, Alta. The important thing about this cylinder is that it has been built in Canada.

The vehicle is under test at Surrey, B.C.-based Powertech Labs Inc., an entirely owned auxiliary of BC Hydro, in collaboration with Fuel Cells Canada. Fuel Cells Canada administers the Hydrogen Highway, a synchronized, large-scale presentation and utilization program intended to accelerate the commercialization of hydrogen and fuel-cell technologies. Nissan joined these organizations in Surrey to start the testing.

“Through Nissan’s advances in hydrogen fuel cell technology, we hope to improve the practicality of fuel cells as a future clean power source,”

These are the words uttered by John Junker-Andersen, Director, Parts, Service and Quality Assurance at NCI. He further added,

“Together with the assistance of Powertech and BC Hydro, we are working hard to make the benefits of fuel cells and their promise of high efficiency and zero emissions a viable reality.”

A fuel cell vehicle is in consequence an electric vehicle, using a fuel cell to alter hydrogen and oxygen into electricity. The electricity is produced by a chemical reaction inside the fuel cell stack when hydrogen from the fuel cylinder merges with oxygen in air. The only by-product is water, making FCVs completely emissions-free. Robb Thompson, Dynetek Industries Ltd said,

“With partners such as Nissan and BC Hydro, we are able to test compressed hydrogen in real world situations,”

“Through these tests, we have demonstrated that compressed hydrogen is the best commercially suitable alternative for the success of the hydrogen economy.”

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Nissan will test the vehicle in a number of environments and drive cycles, including moderate cold-weather, high-speed hill climbs and highway driving, to evaluate the vehicle’s capabilities and the hydrogen fuel system’s performance.

Livio Gambone, Manager, Vehicle Programs at Powertech said,

“As members of the Hydrogen Highway(TM), we are pleased to support Nissan’s vehicle testing program,”

“Our climate and geography, plus access to our seventy MPa hydrogen filling station, make the Vancouver area the best and only place to test the viability and endurance of this FCV.”

The seventy MPa high-pressure hydrogen-powered Nissan X-Trail FCV is the company’s most-recent developmental fuel cell vehicle. Equipped with the first-ever Nissan-constructed fuel cell stack, the X-Trail FCV also boasts a more compact design and increased power. A previous 2003 model offered a cruising range of 350 km, but thanks to improved stack efficiency and a 30 percent increase in the high-pressure Dynetek hydrogen cylinder’s storage capacity, the new X-Trail FCV is expected to achieve a cruising range of more than 500 km.

John Tak, President and CEO, Fuel Cells Canada said,

 “We applaud Nissan Canada’s decision to test their newest hydrogen powered fuel cell vehicle along the Hydrogen Highway(TM),” “As a world-leading centre for hydrogen and fuel cell expertise, British Columbia’s Hydrogen Highway(TM) is an ideal proving ground to test and demonstrate these technologies.”

Nissan has been working on FCV development since 1996. In addition to design and engineering work conducted in Japan, extensive testing and development has also been conducted in other markets, including the United States, where Nissan is a member of the California Fuel Cell Partnership (CaFCP). About Nissan Canada Inc. Nissan Canada Inc. is the Canadian sales, marketing and distribution subsidiary of Nissan Motor Limited and Nissan North America, Inc. With offices in Vancouver (BC), Mississauga (ON), and Kirkland (QC), Nissan Canada directly employs two hundred and ninety staff, while one hundred and forty six independent businesses hold exclusive Nissan dealerships and twenty nine hold exclusive Infinity dealerships. (Jim Motavalli, 2003).

Ten years devotion of Nissan for fuel-cell research has evolved as the latest FCV X-Trail sport/utility vehicle. Nissan engineered and assembled a fuel stack in-house and its most recent unit manages to squeeze the stack’s sophisticated technology in a smaller and lighter package. The new stack develops 120 horse power—35 horse power more than the one fixed to the previous 2003 FCV X-Trail. As a consequence the new model put forward better linear speeding up and response, higher top speed too.

Fuel cell packaging has gifted the new vehicle with more freed passenger space. The lithium-ion battery pack, that is stored under the trunk floor, is also built smaller, permitting for more goods room. In addition to this the smaller fuel-cell unit releases 40 percent extra space under the front seats.

The considerable egg shaped hydrogen tank, which is lined by aluminium in its inner wall and strengthened with carbon fiber in its outer covering posed substantial packaging problem. Nissan has resolved it by placing it under the rear seats with resultant diminished headroom. The texture of the new tank provides it with greater accommodative capacity imparting thirty percent more hydrogen storage capacity that has a great impact on vehicle cruising mileage, sometimes attaining three hundred and twelve miles.

The vehicle X-trial has been observed efficient on the road. Drive of this car is as easy operative as selective drive and tapping into the zero-emission power once the onboard computer system indicates the green signal. Nissan has manufactured the FCV X-trail to bestow the drivers a feeling of normal driving experience a part from the apparent lack of a noxious exhaust. In fact the car is being propelled by the electrical energy generated as a result of discussed chemical reaction. Since a train-like motor sound is audible from the background, however it is never annoying. (Robert L. Olson, 2003).

The X-Trail accelerates readily up to a seventy mile per hour cruising speed and easily achieves a ninety three miles per hour top speed.

Japanese government has approved public road testing and leasing of the Nissan’s latest fuel cell vehicles due to Nissan’s determined hard work and research in the field of fuel cell technology. Let us see when Nissan markets its matchless vehicle for the use of consumers.

References:

Geographical (2003). Cleaning Up the World’s Exhaust Pipes: They’re Quiet, Efficient, Run on Renewable Energy Sources and Their Exhaust Is Just a Cloud of Water Vapour. Could the Rise of Fuel-Cell Vehicles Spell the End of the Internal Combustion Engine? Magazine article; Vol. 75, August

Jack Doyle (2000). Taken for a Ride: Detroit’s Big Three and the Politics of Pollution; Four Walls Eight Windows

Jim Motavalli (2003). Power Plays: Fuel Cells Are Reaching the Market, in What Could Be a $100 Billion Industry; E, Vol. 14, January

Lloyd Dixon, Isaac Porche, Jonathan Kulick (2002). Driving Emissions to Zero: Are the Benefits of California’s Zero Emission Vehicle Program Worth the Costs; Rand

Paul Nieuwenhuis, Peter Wells (2003). The Automotive Industry and the Environment: A Technical, Business and Social Future; CRC Press

Robert L. Olson (2003). The Promise and Pitfalls of Hydrogen Energy: Nonpolluting and Renewable, Hydrogen Energy Holds Great Promise as an Energy Alternative in the Future. Here’s a Look at What’s Right about Hydrogen Energy- and How It Can Go Wrong; The Futurist, Vol. 37, July

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