2013 Unit_Guide MAE3405

Copyright Monash University 2012. All rights reserved. Except as provided in the Copyright Act 1968, this work may not be reproduced in any form without the written permission of the host Faculty and School/Department.

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2013 Unit Guide Template

MAE3405 Flight Vehicle Propulsion

This unit builds on concepts in MAE2402 and relates aircraft and rocket engines to the laws of thermodynamics, various fuel-air power cycles, their real behaviour plus fuel and combustion chemistry. Efficiency and performance of aircraft engines based on piston and gas turbine platforms is examined along with piston and turboprop engines and propeller design for subsonic speed. For jets and turbofan engines, nozzle design for transonic to supersonic speed is covered, as are supersonic engines. The unit concludes with an introduction to rocket motors and their design and performance for both atmospheric and space flight. Mode of Delivery On shore Workload 3 hours lectures, 2 hours prac classes per week

One laboratory class Unit Relationships Prerequisites MAE2402 Chief Examiner Prof Chris Davies Unit Coordinator: A/Prof Damon Honnery Campus: Clayton Phone: 51004 Email: [email protected] Office hours: By email

Campus Coordinator Campus: Phone: Email: Office Hours:

Tutor(s) See Unit Moodle web pages Campus: Phone: Email: Consultation hours:

SEMESTER 2 2012

www.monash.edu


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ACADEMIC OVERVIEW Learning Objectives This unit intended to introduce students to the design, operation and performance of engines used for aircraft and rockets. After successfully completing this unit students will have developed skills and the knowledge to be able to:

1. Understand the thermodynamics of fuel-air power cycles used for aircraft propulsion systems and undertake calculations of their thermodynamic properties.

2. Recognise the differences in real versions of the power cycles relative to their fuel-air analogues.

3. Demonstrate knowledge of the fuels used in aircraft and rocket engines and be able to undertake simple combustion related calculations dealing with these fuels.

4. Understand and undertake calculations on the operation and performance of piston engines, turboprops, and ramjets.

5. Understand and calculate the effects of high speed flight on jets, turbofans and ramjet intakes.

6. Demonstrate knowledge of propeller design through the application of various blade theories.

7. Understand and undertake calculations on propeller operation and performance. 8. Understand and undertake calculations on the operation and performance of

propulsion systems used in rockets operating in the atmosphere and in space. Through lectures, laboratory work and tutorials a student is encouraged to develop an appreciation of:

1. Fuelling requirements of propulsion systems. 2. Aircraft and space flight propulsion systems, their operation and performance. 3. Propeller design, operation and performance based on simple aerodynamic

Graduate Attributes Monash prepares its graduates to be:

1. responsible and effective global citizens who: a. engage in an internationalised world b. exhibit cross-cultural competence c. demonstrate ethical values

2. critical and creative scholars who: a. produce innovative solutions to problems b. apply research skills to a range of challenges c. communicate perceptively and effectively

Engineers Australia stage 1 competencies The Engineers Australia Policy on Accreditation of Professional Engineering Programs requires that all programs ensure that their engineering graduates develop to a substantial degree the stage


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1 competencies. Listed below are the activities in this unit that will help you to achieve these competencies.

Note: that not all stage 1 competencies are relevant to each unit.

Stage 1 competencies Activities used in this unit to develop stage 1 competencies

PE1.1 Knowledge of science and engineering fundamentals

Theoretical lecture material, prescribed texts and recommended reading

PE1.2 In-depth technical competence in at least one engineering discipline

Competence in the thermodynamics of piston engines, gas turbine engines (and derivatives) and rocket motors.

PE1.3 Techniques and resources

PE1.4 General knowledge

Students require a general knowledge of Thermodynamics, heat transfer,. Gas dynamics, fluid mechanics and aerodynamics.

PE2.1 Ability to undertake problem identification, formulation, and solution

Development of engine layout and thermodynamic cycle construction from written description, then calculate cycle properties.

PE2.2 Understanding of social, cultural, global, and environmental responsibilities and the need to employ principles of sustainable development

Examination of alternative aircraft fuels (eg alcohols for piston engines)

PE2.3 Ability to utilise a systems approach to complex problems and to design and operational performance

Examination of complex thermodynamics engines cycles (eg turbofan engine, afterburning turbojet).

PE2.4 Proficiency in engineering design

PE2.5 Ability to conduct an engineering project

PE2.6 Understanding of the business environment

Material on engine design is given which links layout to performance which is linked to aircraft operations: design for purpose.

PE3.1 Ability to communicate effectively, with the engineering team and with the community at large

PE3.2 Ability to manage information and documentation


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PE3.3 Capacity for creativity and innovation

PE3.4 Understanding of professional and ethical responsibilities, and commitment to them

PE3.5 Ability to function effectively as an individual and in multidisciplinary and multicultural teams, as a team leader or manager as well as an effective team member

PE3.6 Capacity for lifelong learning and professional development PE3.7 Professional attitudes

Assessment Summary Assignments There will be five submissions based on the assignment questions listed in this document. There will also be one laboratory session on gas turbines.

Questions are attached to this document. The five assignment submissions are worth 25% of your final marks and are of equal value.

Laboratory You will be assigned a laboratory group for the laboratory session. Each student is to submit an individual laboratory report. Detailed instruction regarding this submission will accompany the laboratory sheets. Failure to attend and submit a laboratory may result in a fail being returned for this unit. The laboratory is worth 5% of your final mark. Examination See the student information index for detail regarding operation of examinations and assessment tasks. The major assessment task in this subject is a three hour long closed book examination. The examination will consist of a number of questions similar but different to those from the assignments. The examination is designed to test not only your ability to solve problems, but your understanding of the related course material as well. See Objectives above

Teaching and Learning Method The learning objectives of this unit as stated in the unit synopsis will be achieved by a combination of lectures, guided learning in tutorials, self learning through assignments and laboratory classes. Objectives 1-9 are designed to provide both a linear and integrated approach to the unit material. For example, foundation engineering science objectives such as 1-3 form the basis of, and are integrated within, the more linear practical and performance oriented material represented by objectives 2-7. Project-based laboratory work involving groups will be used to achieve objectives 2,


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and 6. Self guided learning projects are intended to assist students to broaden their understanding of the material.

Tutorial allocation See tutorial groups on Moodle

Communication, participation and feedback You can also find information on inclusive teaching practices for students with learning disabilities or mental health conditions at: http://www.monash.edu.au/lls/inclusivity/ Feedback Our Feedback to You Feedback on your work is provided via two methods in this unit:

1. Before handing In: By discussing your work with the tutors and unit coordinator. It is essential you take advantage of the problem solving classes to discuss your progress. You are responsible for initiating this process and, as always, our effort will correlate with your effort. This is the most important feedback method.

2. After Handing Back: You will be assigned a work group for your assignments (these are based on lab groups). You will have the chance to discuss the returned assignment with the tutor in the assignment group meeting which occurs in the problem solving class following the submission week.

Your Feedback to Us Monash is committed to excellence in education and regularly seeks feedback from students, employers and staff. One of the key formal ways students have to provide feedback is through SETU, Student Evaluation of Teacher and Unit. The Universitys student evaluation policy requires that every unit is evaluated each year. Students are strongly encouraged to complete the surveys. The feedback is anonymous and provides the Faculty with evidence of aspects that students are satisfied and areas for improvement. For more information on Monashs educational strategy, and on student evaluations, see: http://www.monash.edu.au/about/monash-directions/directions.html http://www.policy.monash.edu/policy-bank/academic/education/quality/student-evaluation-policy.html Previous Student Evaluations of this unit If you wish to view how previous students rated this unit, please go to https://emuapps.monash.edu.au/unitevaluations/index.jsp Required Resources Notes will be provided via the units Moodle pages. Recommended Resources

Texts


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Aircraft performance: Anderson, Aircraft Performance and Design, 1st Edtn, McGraw-Hill, 1999 Thermodynamics: For the thermodynamics component of the subject the following may be of use, Sonntag and Van Wylen, Fundamentals of Classical Thermodynamics, Wiley, 2000 But any general thermodynamics text should be sufficient. Piston Engines Heywood, Internal Combustion Engine Fundamentals, McGraw-Hill, 1988 McMahon, Aircraft Propulsion, Pitman, 1971 Gas Turbines: Cohen, Rogers and Saravananuttoo, Gas Turbine Theory, Longman, 1987 Mattingly, Elements of Gas Turbine Propulsion, McGraw Hill, 1996. Shepherd, Aerospace Propulsion, Elsevier, 1972 Rockets Hill and Peterson, Mechanics and Thermodynamics of Propulsion, 2nd edt, Addison Wesley, 1992.

Field trips None. Additional subject costs None. Examination material or equipment 1. The following scientific calculators that are not programmable, but are capable of 1-variable and 2-variable statistics, (with the authorised Faculty of Engineering or Faculty of Science sticker ) are approved for use in this unit examination: Graphical calculators and programmable calculators are not permitted in exams. APPROVED Scientific Calculators: Caieion: FM-83 Canon: F720, F720i Casio: fx-82, fx-83, fx-85, fx-100, fx-115, fx-350, fx-570, fx-911, fx-991, and fx-992 and fx-3650P series Citizen: SR-135, SR-260, SR-270, SR-275 Hewlett Packard: HP-6s, HP-8s, HP-9s, HP-10s, HP-30s, HP smartcalc-300s Texas instruments: TI-30 and TI-34 series Texet: Albert 2, Albert 3, Albert 5 Sharp: EL-506, EL-509, EL-520 and EL-531WH series 3. IMPORTANT: Only these listed calculators with the authorised Monash University-Science or Monash University-Engineering STICKER will be allowed into the examination by the invigilators.


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The sticker will be available from the Faculty office ground floor building 72. You must bring your calculator with you to the Faculty office at any time during the semester to receive a sticker. We recommend you do this well in advance of the exam. UNIT SCHEDULE

Unit schedule 2012 Topic

(Week) Material

1 Some Important Thermodynamics Concepts (1) Review of first law and Gas processes

Second law Isentropic efficiency

2 Introduction to Air Breathing Engine Performance (1) Piston engine performance

Turbo jet and turbo fan performance

3 Otto and the SI Cycle (2-3) Air standard cycle

Stoichiometry and enthalpy of combustion Fuel-air cycle SI cycle and the Performance of real engines

4 Spark Ignition Engines (4) Typical engine characteristics

Fuel and gas exchange processes Altitude

5 Superchargers and turbochargers (5) Types

Performance

6 Propellers (5-6) Propeller types and design

Classical momentum theory and static performance Simple blade element and vortex theory Introduction to helicopters operation

7 Introduction to Gas Turbines (6-7) Engine Types

Stagnation conditions Air standard gas turbine cycle Overall and system efficiencies

8 Gas Turbines for Propulsion I and II (7-10) Typical engine characteristics

Turboprop engine operation and calculations Turbojet operation and calculations Intake nozzles and propelling nozzles Turbofan operation and calculations Thrust augmentation Ramjets and supersonic intakes

9 Rocket propulsion (10-11) Rocket propulsion systems

Introduction to rocket mechanics Thrust, performance and multistaging Electric Motors

10 Chemical Rocket Motors and Nozzles


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(11-12) Supersonic propelling nozzles Chemical motor performance Design of conical nozzles Solid propellant motors

(13) SWOT VAC

Examination period LINK to Assessment Policy: http://www.policy.monash.edu/policy-bank/academic/education/assessment/assessment-in-coursework-policy.html

ASSESSMENT REQUIREMENTS

See Attachment A for more details.

Criteria for Marking: Marking Scheme: each question will be marked as: 0/5: Not submitted or completely incorrect 1~2/5: Some attempt showing development 2~3/5: Mostly correct, mostly developed 4~5/5: Correct with full development Development means presentation of working, sketches, assumptions, figures, explanations (etc) and where necessary development of equations. Assignment submission Hard Copy Submission: Assignments must include a cover sheet. The coversheet is accessible via the Monash portal page located at http://my.monash.edu.au under the heading Learning and teaching tools. Please keep a copy of tasks completed for your records.

Extensions and penalties

University and faculty policy on assessment Due dates and extensions The due dates for the submission of assignments are given in the previous section. Please make every effort to submit work by the due dates. Students are advised to NOT assume that granting of an extension is a matter of course.

If you need an extension for any of the assignments, you must submit a written request 48-hours before the due time and date, and attach supportive evidence such as medical certificate.

The form should preferably be forwarded as an email attachment, sent to the unit coordinator. The email should be sent from your University email address with your name typed in lieu of signature.

Note that other lecturers cannot grant extensions. Lecturer-in-charge (unit coordinator) will indicate at the time of granting the extension whether any penalty in marks will apply to the submitted work.


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If an extension is granted, the approval must be attached to the assignment.

Late assignment Late submissions of any assessed work will attract a penalty. No late submission will be accepted once the current submissions have been returned. Extensions will only be granted in rare cases and they must be discussed with the subject coordinator at least 48 hours in advance of the submission date if possible. In some cases medical certificates may be required to justify the granting of an extension. Submission of an assignment with your name on it indicates that it is all your own work. If this is not the case you must reference work not yours. See the student resource guide for more information. Remember, you are required to keep an up-to-date copy of all submitted assignments to safeguard against the loss of work through accident or error.

Return dates Assignments will be returned the Friday following the submission date. Assessment for the unit as a whole is in accordance with the provisions of the Monash University Education Policy at:

http://www.policy.monash.edu/policybank/academic/education/assessment/index.html

Returning assignments Done in the Friday Practice Class. Resubmission of assignments Not possible. OTHER INFORMATION Policies Monash has educational policies, procedures and guidelines, which are designed to ensure that staff and students are aware of the Universitys academic standards, and to provide advice on how they might uphold them. You can find Monashs Education Policies at: www.policy.monash.edu.au/policy-bank/academic/education/index.html Key educational policies include:

Plagiarism; Assessment in Coursework Programs; Special Consideration; Grading Scale; Discipline: Student Policy; Academic Calendar and Semesters; Orientation and Transition; and Academic and Administrative Complaints and Grievances Policy.

Graduate Attributes Policy http://www.policy.monash.edu/policy-bank/academic/education/management/monash-graduate-attributes-policy.html


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Student Services The University provides many different kinds of services to help you gain the most from your studies.Contact your tutor if you need advice and see the range of services available at www.monash.edu.au/students Monash University Library The Monash University Library provides a range of services, resources and programs that enable you to save time and be more effective in your learning and research. Go to www.lib.monash.edu.au or the library tab in my.monash portal for more information. Disability Liaison Unit Students who have a disability or medical condition are welcome to contact the Disability Liaison Unit to discuss academic support services. Disability Liaison Officers (DLOs) visit all Victorian campuses on a regular basis.

Website: www.monash.edu/equity-diversity/disability/index.html Telephone: 03 9905 5704 to book an appointment with a DLO; Email: [email protected] Drop In: Equity and Diversity Centre, Level 1, Building 55, Clayton Campus.

Your Feedback to Us Monash is committed to excellence in education and regularly seeks feedback from students, employers and staff. One of the key formal ways students have to provide feedback is through the Student Evaluation of Teaching and Units (SETU) survey. The Universitys student evaluation policy requires that every unit is evaluated each year. Students are strongly encouraged to complete the surveys. The feedback is anonymous and provides the Faculty with evidence of aspects that students are satisfied and areas for improvement. For more information on Monashs educational strategy, see: www.monash.edu.au/about/monash-directions/directions.html and on student evaluations, see: www.policy.monash.edu/policy-bank/academic/education/quality/student-evaluation-policy.html Previous Student Evaluations of this Unit We have identified that students who undertake the laboratory in the first weeks of the semester require additional assistance with the laboratory. More details have been provided on the Moodle web page for this purpose. If you wish to view how previous students rated this unit, please go to https://emuapps.monash.edu.au/unitevaluations/index.jsp


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Attachment A


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MAE3405 Flight Vehicle Propulsion 2013 Information, problems and assignments

Unit : MAE3405 Flight Vehicle Propulsion

This unit builds on concepts in MAE2402 and relates aircraft and rocket engines to the laws of thermodynamics, various fuel-air power cycles, their real behaviour plus fuel and combustion chemistry. Efficiency and performance of aircraft engines based on piston and gas turbine platforms is examined along with piston and turboprop engines and propeller design for subsonic speed. For jets and turbofan engines, nozzle design for transonic to supersonic speed is covered, as are supersonic engines. The unit concludes with an introduction to rocket motors and their design and performance for both atmospheric and space flight.


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Subject Coordinator : Associate Professor Damon Honnery Room : Clayton G15/31 Email : [email protected] Details of this unit can be found at http://www.monash.edu.au/pubs/handbooks/units/MAE3405.html Student Information Index All students are advised to read the information found in the student information index located at: http://www.monash.edu.au/students/ you are also encouraged to look through the student resource information on the Faculty and Department web pages. Moodle Page There is a Moodle page for this unit. This site contains a large amount of information as well as data and links to interesting web pages. The Faculty of Engineering MAE3405 Unit Guide can also be found on site. The unit guide provides more detailed information than listed here. Assessment: This subject will have three forms of assessment: Examination: 70% (three hours closed book). Assignments and Laboratories: 30% Classes For each week of the semester there will be three hours of lectures and a two hour problem solving session. You will also each have a 1 hour laboratory session which will operate during the problem solving session. You are expected to undertake at least 7 additional hours per week of private study to complete the assessment tasks. Attendance Attendance at the laboratory is compulsory. Failure to attend and submit a laboratory report may result in a fail being returned for this unit. Class Notes Class notes are listed on the Moodle page. Some notes will be provided in class (mainly worked examples). You will have to copy these down. Problem Solving Classes Problem solving classes are intended to assist with assignments. They will not operate in the first week of semester. To benefit from these classes you should be up to date with your work and reading. Lecture Topics The lecture topics are listed in the table below along with their approximate week of delivery. The timing of the lecture material is necessarily approximate as more or less time might be spent on individual topics depending on the inclination and interest of the students. Assignments There will be five submissions based on the assignment questions listed in this document. There will also be one laboratory session on gas turbines.

Questions are attached to this document. The five assignment submissions are worth 25% of your final marks and are of equal value.

Laboratory You will be assigned a laboratory group for the laboratory session. Each student is to submit an individual laboratory report. Detailed instruction regarding this submission will accompany the


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laboratory sheets. Failure to attend and submit a laboratory may result in a fail being returned for this unit. The laboratory is worth 5% of your final mark. Examination See the student information index for detail regarding operation of examinations and assessment tasks. The major assessment task in this subject is a three hour long closed book examination. The examination will consist of a number of questions similar but different to those from the assignments. The examination is designed to test not only your ability to solve problems, but your understanding of the related course material as well. See Objective section below. Submission Penalties Late submissions of any assessed work will attract a penalty. No late submission will be accepted once the current submissions have been returned. Extensions will only be granted in rare cases and they must be discussed with the unit coordinator at least 48 hours in advance of the submission date if possible. In some cases medical certificates may be required to justify the granting of an extension. Submission of an assignment with your name on it indicates that it is all your own work. If this is not the case you must reference work not yours. See the student information index for more detail. Remember it is better to hand in an incomplete assignment, than not to hand in anything at all. Suggested Reading While the class notes are comprehensive, greater understanding of the unit material requires you to read more widely than just these notes. The following books are suggested to assist you to do this; there is of course an abundance of material on the internet. Aircraft performance: Anderson, Aircraft Performance and Design, 1st Edtn, McGraw-Hill, 1999 Thermodynamics: For the thermodynamics component of the subject the following may be of use, Sonntag and Van Wylen, Fundamentals of Classical Thermodynamics, Wiley, 2000 But any general thermodynamics text should be sufficient. Piston Engines Heywood, Internal Combustion Engine Fundamentals, McGraw-Hill, 1988 McMahon, Aircraft Propulsion, Pitman, 1971 Gas Turbines: Cohen, Rogers and Saravananuttoo, Gas Turbine Theory, Longman, 1987 Mattingly, Elements of Gas Turbine Propulsion, McGraw Hill, 1996. Shepherd, Aerospace Propulsion, Elsevier, 1972 Rockets Hill and Peterson, Mechanics and Thermodynamics of Propulsion, 2nd edt, Addison Wesley, 1992. Student Consultation Times The best time to discuss this unit is during the problem solving classes. Should you wish to see me outside the normal hours of the unit, the best time to catch me for a short consultation is between 9:30 and 10:00am Tuesday to Friday, or after 4:00pm most days but Friday. For a longer consultation I should be contacted via email for an appointment.


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READ THIS PAGE CAREFULLY AND OFTEN Objectives of this Unit This unit is intended to introduce students to the design, operation and performance of engines used for aircraft and rockets. After successfully completing this unit students will have developed skills and the knowledge to be able to: 1. Understand the thermodynamics of fuel-air power cycles used for aircraft propulsion systems

and undertake calculations of their thermodynamic properties.

2. Recognise the differences in real versions of the power cycles relative to their fuel-air analogues.

3. Demonstrate knowledge of the fuels used in aircraft and rocket engines and be able to undertake simple combustion related calculations dealing with these fuels.

4. Understand and undertake calculations on the operation and performance of piston engines, turboprops, and ramjets.

5. Understand and calculate the effects of high speed flight on jets, turbofans and ramjets intakes.

6. Demonstrate knowledge of propeller design through the application of various blade theories.

7. Understand and undertake calculations on propeller operation and performance.

8. Understand and undertake calculations on the operation and performance of propulsion systems used in rockets operating in the atmosphere and in space. Through lectures, laboratory work and tutorials a student is encouraged to develop an appreciation of :

9. Fuelling requirements of propulsion systems.

10. Aircraft and space flight propulsion systems, their operation and performance.

11. Propeller design, operation and performance based on simple aerodynamic principles. Feedback (and your role in it) Feedback on your work is provided via two methods in this unit:

3. Before handing In: By discussing your work with the tutors and unit coordinator. It is essential you take advantage of the problem solving classes to discuss your progress. You are responsible for initiating this process and, as always, our effort will correlate with your effort. This is the most important feedback method.

4. After Handing Back: You will be assigned a work group for your assignments (these are based on lab groups). You will have the chance to discuss the returned assignment with the tutor in the assignment group meeting which occurs in the problem solving class following the submission week.


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Lecture Topics and Approximate Week of Delivery- All notes are on Blackboard

Topic (Week)

Material

1 Some Important Thermodynamics Concepts (1) Review of first law and Gas processes

Second law Isentropic efficiency

2 Introduction to Air Breathing Engine Performance (1) Piston engine performance

Turbo jet and turbo fan performance

3 Otto and the SI Cycle (2-3) Air standard cycle

Stoichiometry and enthalpy of combustion Fuel-air cycle SI cycle and the Performance of real engines

4 Spark Ignition Engines (4) Typical engine characteristics

Fuel and gas exchange processes Altitude

5 Superchargers and turbochargers (5) Types

Performance

6 Propellers (5-6) Propeller types and design

Classical momentum theory and static performance Simple blade element and vortex theory Introduction to helicopters operation

7 Introduction to Gas Turbines (6-7) Engine Types

Stagnation conditions Air standard gas turbine cycle Overall and system efficiencies

8 Gas Turbines for Propulsion I and II (7-10) Typical engine characteristics

Turboprop engine operation and calculations Turbojet operation and calculations Intake nozzles and propelling nozzles Turbofan operation and calculations Thrust augmentation Ramjets and supersonic intakes

9 Rocket propulsion (10-11) Rocket propulsion systems

Introduction to rocket mechanics Thrust, performance and multistaging Electric Motors

10 Chemical Rocket Motors and Nozzles (11-12) Supersonic propelling nozzles

Chemical motor performance Design of conical nozzles Solid propellant motors


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Assignment Submissions

Students: You must keep a copy of your assignment

The assignments are to be written on A4 sheets, single sided, corner stapled. Do not place the assignment in a folder (clear plastic or otherwise). An assignment cover sheet is to be attached to every submission. Initial the top right-hand corner of each page. Working must be neat and able to be read- any work that cannot be read will not be marked. Complete answers are required to gain full marks (assumptions, working, figures, force

balances, graphs etc where required). Penalties apply for late assignments. Failure to follow any or all of these instructions might result in your assignment not being

marked.

You will need to check the MAE3405 Moodle page for data sheets etc to do some of these questions.

Assignment Questions and due dates The following questions are to be handed in by the due date and time in the tutorial. They will not be accepted at any other time or place. Assignments will be returned in the tutorial of the following week during which time the solutions and common problems will be discussed. Questions Time and Date Due 2 and 4 By 4:00pm in the tute of week 4 (23/8) (check tutor group)* 6 and 13 By 4:00pm in the tute of week 6 (6/9) (check tutor group) 18 and 24 By 4:00pm in the tute of week 8 (20/9) (check tutor group) 25 and 28 By 4:00pm in the tute of week 10 (11/10) (check tutor group) 30 and 33 By 4:00pm in the tute of week 12 (25/10) (check tutor group) *see below You should attempt all questions listed. Assistance to questions not submitted as assignments will be given in the tutorials but no assistance will be given to help with assignment questions. The tutors have been advised not to answer any questions relating to the 10 assignment questions listed above. Questioned marked * are typical examination questions. *You will each be assigned a group for labs, assignment and tutorial submissions. You must make sure you submit your assignment to the correct group on the day the assignment is due. Assignment will be returned the following week in your groups during which you will have the chance to discuss the returned assignment. Marking Scheme: each question will be marked as: 0/5: Not submitted or completely incorrect 1~2/5: Some attempt showing development 2~3/5: Mostly correct, mostly developed 4~5/5: Correct with full development Development means presentation of working, sketches, assumptions, figures, explanations (etc) and where necessary development of equations.


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Question 1 Taking the data for the surface level atmospheric composition of Mars (table A.9 in the first chapter of the notes), calculate the (i) average atmospheric molecular weight of the atmosphere noting that table A.9 lists concentrations as volume fractions, (ii) the gas constant (R kJ/kg-K) and (iii) the ratio of specific heats () (Cp=0.523 kJ/kg-K and mole weight 39.95 kg/kmole for Argon). [Answer: (i) 43.41 kg/kmole; (ii) 0.195 kJ/kg-K; (iii) 1.32]

Question 2 An aircraft engine with constant mass flow rate of 0.2 kg/s operates in an environment such that 15 kW of heat is lost from its surfaces through radiant and convective processes. Fuel flow is equal to 1/15 of the inlet mass flow and provides 45 MJ of energy per kg of fuel to the engine. The inlet gas to the engine can be approximated by air at SSL conditions; while the exhaust mass flow into the atmosphere is a mixture of 65% N2, 15% CO2 and 20% water (gas) by mass at 900o C. For an inlet pipe diameter of 0.125m and exhaust pipe diameter of 0.15m, (i) determine the power output of the engine and (ii) the engines efficiency. Use a reference temperature of To=25oC for your calculations. [Assignment question]

Question 3 A small gas turbine engine has the following flight conditions. You may assume the exhaust pressure to atmospheric.

Altitude 6500m Flight speed Mach number 0.398 Intake diameter 0.300m Exhaust diameter 0.285m Exhaust speed 950kph Exhaust gas temperature 2500C Exhaust gas constant 250J/kg-K Fuel density 850kg/m3

(a) Determine the ratio of fuel mass flow to air mass flow for the engine. [Ans: 0.0279] (b) Calculate the net thrust developed by the engine and the thrust specific fuel consumption

(in kg/N.h) [Ans: 806.2 N; 0.688 kg/N-h] (c) What percentage of the gross thrust is used to overcome ram drag? [Ans: 46.1%]

Question 4 In an air standard Otto cycle the maximum and minimum temperatures are 1400oC and 15oC. The heat supplied to the cycle is 800 kJ/kg. (i) Calculate the compression ratio and cycle efficiency. (ii) Calculate also the ratio of maximum to minimum pressures in the cycle assuming SSL as minimum cycle pressure. (iii) What is the maximum possible efficiency that could be obtained from the thermodynamic states that make up the cycle? [Assignment question] Question 5 Methanol (CH3OH) is a possible alternative SI engine fuel. For a stoichiometric fuel/air mixture, determine (i) the air to fuel ratio, (ii) the LHV (kJ/kg) for gaseous fuel and (iii) the percentage reduction in LHV assuming the fuel to be liquid. [Ans: (i) 6.43; (ii) 21.12 MJ/kg; (iii) 5.54%]


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Question 6 A 4-cylinder SI aircraft engine operates at SSL on the fuel-air Otto cycle. Its total swept volume is 2.0 Litres, and the clearance volume is 60 cm3 per cylinder. Assume the fuel is gaseous isooctane and the A/F ratio is stoichiometric. Calculate (i) the LHV (kJ/kg) of the fuel (ii) the fuel-air cycle thermal efficiency, (iii) the cycle MEP. [Assignment question]

Question 7 Measurement of the exhaust from a piston engine operating on a hydrocarbon fuel reveals the following gas concentrations: CO2 9.14%, CO 5.1%, H2O 13.7% and H2 2.31%. Nitrogen makes up the balance. The mass flow rate of the exhaust is 0.1 kg/sec. Determine: (i) the mass flow rate (kg/s) of each of the exhaust species, (ii) the fuel flow rate and air to fuel ratio and (iii) a possible fuel molecule in the form CnH2n+2 (find n). [Ans: (ii) 12.57; (iii) n=12.58]

Question 8 For the 4-clyinder Lycoming 0-360 engine operates on aviation gasoline (table A.3 chapter 1) determine the following for this at SSL: (a) The air standard thermal efficiency of the engine. [Ans: 57.2%] (b) The valve clearance space. [Ans: 0.197 litres/cylinder] (c) The BMEP for take-off and the 65% cruise condition. [Ans: 944 kPa; 758 kPa] (d) The brake thermal efficiency of the engine at take-off assuming an air to fuel ratio of 14.7 and volumetric efficiency of 85%. [Ans: 28.8%] Question 9 For the 4 cylinder, 4-stroke aircraft engine below, determine its power output and its brake thermal efficiency. Assume the fuel is liquid isooctane. [Ans: 66.8 kW; 40%]

Quantity Value Quantity

Value

IMEP 1.0MPa Volumetric efficiency 78% Bore 0.1m Mechanical Efficiency 85% Stroke 0.12m RPM 2500 Altitude 3000m Air to fuel ratio 14.8 True airspeed 175kph

Question 10 The engine dynamometer test results for a 4-stroke air-cooled 4-cylinder horizontally opposed spark ignition aircraft engine operating on isooctane are listed in the table below.

Speed RPM

Brake Load N

Air kg/min

Fuel L/min

2100 462.135 2.311 0.222 2300 480.838 2.457 0.238 2500 502.890 2.654 0.260 2700 497.984 2.839 0.279 2900 470.747 2.966 0.292

The dynamometer used had a torque arm radius of 0.4m. The test cell conditions on the day of the test were a temperature of 25C, and pressure of 101.3kPa. The fuel used was aviation gasoline. The cylinder bore is 82.6mm, and stroke 102mm.


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Calculate and plot against speed (i) torque, (ii) brake power, (iii) SFC, (iv) BMEP, (v) volumetric efficiency, (vi) brake thermal efficiency, (vii) air to fuel ratio and (viii) equivalence ratio. Question 11 (i) Assuming the linear relationship between power and density in the notes, construct a plot of maximum brake power against altitude up to 8,000m for the engine in question 10. (ii) Determine the maximum ceiling of an aircraft using this engine for an equivalent airspeed of 150knots and ceiling altitude drag force 350N. You may also assume a constant propulsive efficiency of 85%.[Ans: (i) eg z=2000m, 43.5kW; (ii) ~3250m] Question 12 An engine with mass flow rate of 0.1 kg/s has an inlet manifold pressure boost of 1.3 provided by a supercharger. If flying at an altitude of 2000 m, (i) determine the power required to drive the supercharger assuming a mechanical efficiency of 90% and isentropic efficiency of 80%. (ii) If an intercooler was used to reduce the supercharger temperature increase by 50%, determine the increase in charge air density relative to atmospheric. [Ans: (i) 3.0 kW; (ii) 24%] Question 13 An in-line 6-cylinder water cooled 4-stroke aircraft engine of 75mm bore and 100mm stroke has a brake power output of 110kW at 2800RPM. The volumetric efficiency at this operating condition referred to SSL is 80%. The engine is now fitted with a mechanically driven supercharger with an isentropic efficiency of 70% and pressure ratio of 1.6. The supercharged version has a volumetric efficiency of 100% referred to supercharger delivery pressure and temperature. Assume the indicated power developed per unit volume flow rate of induced air at ambient conditions is the same for normal aspiration and supercharging. Calculate the net increase in brake power resulting from the supercharger. Take the mechanical efficiency of the engine at 80% in both cases and the mechanical efficiency of the supercharger drive as 95%. [Assignment question] Question 14* A 2m diameter propeller is being tested on the 4 cylinder SI engine whose data is listed below runs on avegas. If the test is done at an altitude of 2000m, determine the static thrust developed. Assume the engine operates on the fuel/air Otto cycle. [Ans: 3.25 kN] Piston Engine Quantity Value

Quantity Value

Compression ratio 7.5 Combustion efficiency 99% Bore 0.1m Mechanical Efficiency 85% Stroke 0.125m Volumetric efficiency 80% RPM 2700 Air to fuel ratio 14.5 Cp reactants 1.055kJ/kg-K Cp products 1.486kJ/kg-K Cv reactants 0.768kJ/kg-K Cv products 1.199kJ/kg-K

Question 15* A helicopter hovers at 1000m. It has a mass of 750kg. Its main rotor is made up of two blades each having a length of 4m. The tail rotor also has two blades each having a length of 0.75m. If the power required to drive the tail is 10% of that required to drive the main rotor and the hovering condition can be considered a static thrust case, determine: (i) the volumetric fuel consumption per hour, (ii) the brake specific fuel consumption in kg/kWh and (iii) the thermal efficiency of the engine. Specifications of the SI 4-stoke engine are listed below. Quantity Value

Quantity Value

Bore 0.1m Combustion efficiency 98%


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Stroke 0.12m Mechanical Efficiency 90% RPM 2500 Volumetric efficiency 85% Cylinders 6 Air to fuel ratio Stoichiometric Fuel approximated by CH2.2 Fuel Avgas Cp (fuel & air) 1.055kJ/kg-K Cp (exhaust products) 1.486kJ/kg-K Cv (fuel & air) 0.768kJ/kg-K Cv (exhaust products) 1.199kJ/kg-K

Question 16* A three bladed aircraft propeller with symmetric section is to be tested at SSL conditions under zero advance speed. The section lift coefficient, angle of attack and chord are given as functions of the blade radius. From the data below, estimate the thrust if the blade speed is set to 2700RPM on the test bed. [Ans: 7.2kN]

Section Lift coefficient gradient a = 0.1[1+0.1(r/R] (deg-1) AOA as a function of bade radius, r = [15-10(r/R)] (deg) Chord as a function of blade radius, r c = (R/5)[1-(r/R-0.5)2] (m) Hub radius RH = 0.1R (m) Blade radius 1.0m

Question 17* An intercooled turbocharged 4 cylinder 4-stroke spark ignition aircraft piston engine fuelled by avgas drives a 1.8m diameter twin blade propeller. Data on the engine is listed in the table below. The turbocharger provides a pressure ratio of 1.3 at an isentropic efficiency of 85%. It is located between the intake and fuel injection system. The turbochargers intercooler reduces the turbocharger temperature rise by 75%. Assuming the engine to operate on the fuel/air Otto cycle, calculate the static thrust available at SSL using Froude theory. [Ans: 4.3kN] Piston Engine Quantity Value

Quantity Value

Compression ratio 7.0 Combustion efficiency 95% Bore 0.1m Mechanical Efficiency 90% Stroke 0.12m Volumetric efficiency 100% RPM 2500 Air to fuel ratio 14.5 Cp (fuel & air) 1.055kJ/kg-K Cp (exhaust products) 1.486kJ/kg-K Cv (fuel & air) 0.768kJ/kg-K Cv (exhaust products) 1.199kJ/kg-K

Question 18 Using the McCormick approximation to blade propeller theory, determine the thrust power, torque power and efficiency of a 3 bladed 5868-9 Clarke-Y section propeller with a diameter of 2.0m, rotational speed of 2700RPM, advance speed of 150kph and pitch of 150 at 75% of the blade radius operating at SSL. Assume that the blade lift slope can be approximated by a=0.1(1.0+t/c)/deg where t is the section thickness and the hub occupies about 5% of the blade radius. You may also assume that section drag polar for the blade is given by, Cd=Cdmin+0.01(Cl-0.15)2 where Cdmin=0.004+0.017(t/c). Additional blade data from page 89 of notes. [Assignment question] Question 19


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A helicopter with total mass 600 kg, drag coefficient 0.35 and rotor diameter 10 m, moves with a forward speed of 25 knots at an altitude of 1000m. By determining the relative speed of the air to the blade, find the power required. [Ans: 12.9 kW] Question 20 A single spool turbojet with a fixed overall pressure ratio of 20 and maximum cycle temperature of 1400 K operates with an ideal compressor, turbine and nozzles. Assume here also that the specific heats are the same for cold and hot sides and fuel mass flow is negligible. (i) For a mixed air speed of Mach=0.8, plot the specific thrust and TSFC against altitude up to 10,000m. (ii) For a fixed altitude of 5,000m, plot the specific thrust for air speeds ranging from Mach=0 to 0.8. Question 21 A turbojet is operating with the conditions below. Quantity Value

Quantity Value

Compressor Ratio 9.0 Compressor Cp 1.005kJ/kgK Turbine Inlet Temp 1250K Compressor 1.4 Isentropic Efficiencies Turbine Cp 1.148kJ/kgK Compressor 87% Turbine 1.333 Turbine 87% Exhaust Gas Constant R 0.287kJ/kgK Intake 95% Engine Mass Flow 15kg/s Propelling Nozzle 95% Airspeed 260m/s Mechanical Efficiency 99% Altitude 7000m Combustion Efficiency 98% Combustor Pressure drop 6% Calculate the propelling nozzle area required, the net thrust developed and the TSFC using the combustor temperature diagram from the notes page 162. [Ans: 0.0644 m2; 8.86 kN; 0.120 kg/N-h] Question 22 The exhaust gases in the jet pipe of the engine above are reheated to 2000K by supply of Jet A1 fuel to an afterburner; the combustion pressure loss incurred is 3% of the pressure at the outlet from the turbine. Calculate the percentage increase in nozzle area required if the mass flow is to be unchanged, the percentage increase in net thrust and fuel flow rate. [Ans: 49%; 63%; 144%] Question 23* For the single spool turbo-prop engine below, determine the thrust power assuming the propeller to be 85% efficient and the propelling nozzle pressure ratio to be 1.3. [Ans: 1.8MW] Quantity Value

Quantity Value

Compressor Ratio 8.0 Combustion Pressure drop 4% Turbine Inlet Temp 1200K Compressor Cp 1.005kJ/kgK Isentropic Efficiencies Compressor 1.4 -Compressor 87% Turbine Cp 1.148kJ/kgK -Turbine 90% Turbine 1.333 -Intake 93% Exhaust Gas Constant R 0.287kJ/kgK -Propelling Nozzle 95% Intake Nozzle Area 0.1m2 Spool Efficiency 99% Altitude 5000m Combustion Efficiency 98% Airspeed 125m/s Gear Box efficiency 90%


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Question 24* A new turbo-prop engine is being designed. As well as having a gas generator spool, the engine also has a second power spool which drives the propeller through an epicyclic gear box. As well as having a combustor located between the compressor and turbine of the gas generator spool, the engine also has a re-heat combustor between the exit of the gas generator turbine and the power turbine. This is designed to increase thrust power. For the engine specifications below, determine the thrust power for a take-off speed of 75knots and propulsive efficiency 85% at SSL. [Assignment question] Quantity Value

Quantity Value

Compressor Ratio 10 Compressor Cp 1.005kJ/kg-K Combustor F/A ratio 0.015 Compressor 1.4 Isentropic Efficiencies Turbine Cp 1.148kJ/kg-K - Compressor 85% Turbine 1.333 - Turbine and power turb. 90% Exhaust gas constant R 0.287kJ/kg-K - Intake (subsonic) 95% Intake nozzle area 0.2m2 - Propelling nozzle 95% Reheat F/A ratio 0.005 Gas generator spool eff. 99% Reheat comb. eff 98% Combustor efficiency 98% Reheat pressure drop 2% Combustor pressure drop 3% Gear box efficiency 85% Propelling noz. press ratio 1.2 Fuel Jet A1 Question 25* The following data is for a twin-spool turbofan gas turbine engine, with the fan driven by the LP turbine and the compressor by the HP turbine. Separate cold and hot nozzles are used. Determine the net thrust and TSFC. [Assignment question] Quantity Value

Quantity

Overall Pressure Ratio 20.0 Compressor Cp 1.005kJ/kgK Turbine Inlet Temp 1300K Compressor 1.4 Fan Pressure Ratio 1.7 Turbine Cp 1.148kJ/kgK Compressors, Fan and Turbine isentropic Eff.

90%

Turbine 1.333 Exhaust Gas Constant R 0.287kJ/kgK

Intake Isentropic Eff. 95% Airspeed Mach 0.8 Propelling Nozzles Eff. 95% Altitude 10,000m Spool Mechanical Eff. 99% Area Cold Nozzle 0.8m2 Combustion Efficiency 98% By-pass ratio 4 Combustion Pressure drop

4%

Question 26 For a ramjet, plot the specific thrust and TSFC against Mach number for speeds, from Mach number 0.75 up to 5, for an altitude of 20,000m. Assume that the maximum flame temperature is 2200K and combustion pressure drop is 1% of the ram pressure. The intake may be considered as being divided into two sections: supersonic and subsonic. In the supersonic section, should the Mach number be greater than 1, use is made of a normal shock in the inlet plane to reduce the airspeed to subsonic conditions. The subsonic component of the inlet leading to the combustor section has an isentropic efficiency of 95% while the converging propelling nozzle has an


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isentropic efficiency of 95%. Assume the usual air and product property data. Comment on the results. [Ans: Ma=1.75 Fs= 730 Ns/kg TSFC= 0.25 kg/N-h] Question 27 Repeat question 26 but assume after an airspeed of Mach=1 an isentropic converging-diverging propelling nozzle is used to fully expand the exhaust gas to atmospheric pressure. Given the nozzle area ratio, is acceleration from Mach 1 to Mach 5 using the same nozzle system practical? [Ans: Ma=1.75 Fs= 792 Ns/kg TSFC= 0.23 kg/N-h] Question 28* The single spool turbojet with afterburner, see table below, operates at an airspeed of Mach=1.5. At this speed the intake is designed to operate with a single normal shock entry after which the flow is subsonic. Both combustor and afterburner operate on aviation turbine fuel. For an altitude of 15,000m, determine the net thrust and TSFC in kg/N-h. [Assignment question] Quantity Value

Quantity Value

Compressor Ratio 10 Compressor Cp 1.005kJ/kg-K Turbine Inlet Temp 1350K Compressor 1.4 Isentropic Efficiencies Turbine Cp 1.148kJ/kg-K - Compressor 87% Turbine 1.333 - Turbine 87% Exhaust gas constant R 0.287kJ/kg-K - Intake (subsonic) 95% Engine air mass flow 20kg/s - Propelling nozzle 95% After burner efficiency 95% Mechanical efficiency 99% Afterburner temperature 2000K Combustor efficiency 98% Afterburner pressure

drop 5%

Combustor pressure drop 6%

Question 29 A single stage rocket is being designed to launch a satellite. The launch angle of 800 is used for a programmed burn time of 50 sec. The mass of the probe is 50kg, and over all structure mass 1500kg. The rocket motor has a combustion chamber pressure of 3.0MPa. If a convergent/divergent nozzle is used with throat area 0.1m2, and it is designed to have an exit pressure equal to that found at a pressure altitude of 15km. Calculate using the rocket fuel data table in the notes for following fuels (i) Kerosene/O2 and (ii) H2/O2 : (a) The exhaust exit velocity. [Ans: (i) 3061 m/s; (ii) 4423 m/s] (b) The propellant mass flow. [Ans: (i) 176 kg/s; (ii) 122 kg/s] (c) The thrust. [Ans: (i) 0.54 MN; (ii) 0.54 MN] (d) The specific impulse. [Ans: (i) 312 s; (ii) 451 s] (e) Total propellant mass and its volume. [Ans: (i) 8815 kg; 8240 m3; (ii) 6095 kg; 23175 m3] (f) The velocity increment [Ans: (i) 5333 m/s; (ii) 6573 m/s] (g) Burnout height and coast height. [Ans: (i) 89.9 km; 1966 km; (ii) 119 km; 3483km ] Question 30* A single stage rocket is used to launch a satellite. A launch angle of 850 is used for a programmed burn time of 75 sec. The mass of the probe is 100kg, and mass of the rocket structure 3000kg. The rocket motor has a combustion chamber pressure of 3.0MPa and temperature of 2750oC. A convergent/divergent nozzle is used with throat area 0.1m2. The nozzle is designed to have an exit pressure equal to that found at SSL. Exhaust gas specific heat ratio is 1.15, and molecular weight 22 kg/kmole. Determine (i) the launch thrust at SSL; and (ii) the motor burnout height assuming the nozzle exit velocity remains constant at its launch value. [Assignment question]


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Question 31 A rocket is being designed to launch a deep space probe. The total mass of the rocket is limited to 1000kg resulting in a structure stage fraction of 0.075 (constant for any number of stages). For the fuel used the rocket is expected to have an effective exhaust velocity of 4500m/s. Determine the variation in possible payload and total propellant mass if the rocket is made up of either (i) 1 or (ii) 2 stages. [Ans: (i) 8 kg; 917kg; (ii) 45 kg; 864 kg]

Question 32 Undertake a force balance on a rocket undergoing atmospheric flight that includes the effects of gravity, drag and thrust. Assume that gravity, thrust and drag are all functions of altitude. Based on the data below, calculate the gravity turn trajectory f(z,x) from take off to the end of the fuel burn. The rocket is a single stage rocket with a probe mass of 10kg, structure mass 50kg and 1000kg of H2/O2 propellant. The rocket motor has a combustion chamber pressure of 3.0MPa and a convergent/divergent nozzle is used with throat area 0.1m2. Assume the nozzle exit pressure is fully expanded to the altitude condition. The launch angle is 80deg and you may assume an effective area of CdA=0.1m2. Solution of this problem will require numerical integration of the force balance over a small time interval until the total propellant mass is consumed. Question 33* A rocket motor is fuelled by a stoichiometric mix of hydrogen and oxygen. The fuel and oxidiser enter the combustion chamber at a temperature of 23oC, then burn at a constant chamber pressure of 7.0Mpa. The efficiency of the combustor is 90%. The formation enthalpy of the water vapour produced from the combustion process is 241.827MJ/kmole. For an altitude of 20,000m, determine: [Assignment question] (i) The thrust produced assuming a converging nozzle with exit diameter 0.5m and isentropic efficiency 95%. (ii) Whether the thrust produced would be increased over (i) above by adding a diverging section with the same isentropic efficiency to the nozzle that expands the exhaust gases to atmospheric pressure for the given altitude.

2013 Unit_Guide MAE3405

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