2013 Unit_Guide MAE3405

2013 2013 Uni Unitt Gui de Temp Template late

MAE3405

Fligh li ghtt Ve Vehicle hic le Propuls rop ulsio ion n 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 Workload Unit Relationship Relationship s Prerequisites Chief Examiner Unit Coordinator: Campus: Phone: Email: Office hours:

On shore 3 hours lectures, 2 hours prac classes per week One laboratory class MAE2402 Prof Chris Davies A/Prof Damon Honnery Honnery Clayton 51004 [email protected] By email

Campus Campus Coordinator Campus: Phone: Email: Office Hours: Tutor(s) Campus: Phone: Email: Consultation hours:

See Unit Moodle web pages

SEMESTER 2 2012

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. 1

www.monash.edu

ACA DEMIC 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 of fuel-air power cycles used used for aircraft propulsion propulsion systems and undertake calculations of their thermodynamic properties. 2. Recognise the differences in real versions versions of the power cycles relative to their their fuelair analogues. 3. Demonstrate knowledge knowledge of the fuels used used in aircraft and rocket engines and and be able to undertake simple combustion related calculations dealing with these f uels. 4. Understand and undertake calculations calculations on the operation and performance of piston engines, turboprops, and ramjets. 5. Understand and calculate the effects of high speed flight flight on jets, turbofans and and ramjet intakes. 6. Demonstrate knowledge knowledge of propeller design design through the application application of various blade blade theories. 7. Understand and and undertake calculations on propeller operation and performance. performance. 8. Understand and and undertake calculations on on the operation operation and performance 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 propulsion systems. 2. Aircraft and space space flight propulsion propulsion systems, their operation and performance. 3. Propeller design, design, operation and performance based based on simple simple aerodynamic aerodynamic Graduate Attributes Monash prepares its graduates to be: 1. responsible and effective global citizens who: a. engage in an an internationalised internationalised world b. exhibit cross-cultural competence c. demonstrate ethical values 2. critical and creative scholars who: a. produce innovative solutions to problems problems b. apply research 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 graduates develop to a substantial degree the stage 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. 2

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

Activ ities 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 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, Thermodynamics, heat transfer,. Gas dynamics, fluid mechanics and aerodynamics.

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

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

PE2.2 Understanding Understanding of social, cultural, global, 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 complex problems and to design and operational performance

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

PE2.4 Proficiency in engineering engineering design PE2.5 Ability to conduct an engineerin engineering g project project PE2.6 Understanding Understandi ng 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 communicate effectively, with the the engineering team and with the community at large

PE3.2 Ability to manage information and documentation 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. 3

PE3.3 Capacity for creativity and innovation

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

PE3.5 Ability to function effectively effectively as an individual 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 lifelong learning and professional development PE3.7 Professional attitudes

As ses sm ent Sum mar y As si gn men t s 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 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 Teaching and Learnin g Method 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, 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. 4

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 Feedback t o You Feedback on your work is provided via two methods in this unit: 1. Before handing In: In: By 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: 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 Feedback t o 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 University’s 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 Monash’s 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-evalua http://www.policy.monash.edu/policy-bank/academic/edu cation/quality/student-evaluationtionpolicy.html Previous Previous Student Evaluations Evaluations of this u nit If you wish to view how previous students rated this unit, please go to https://emuapps.monash.edu.au/unitevaluations/index.jsp Requi Requi red Resour Resour ces Notes will be provided via the unit’s Moodle pages. Recomm Recomm ended Resour Resour ces Texts 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. 5

Ai rc raf t per fo rm anc e: Anderson, Aircraft Anderson, Aircraft Performance and Design, 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, Thermodynamics, Wiley, 2000 But any general thermodynamics text should be sufficient. Piston Engines Heywood, Internal Combustion Engine Fundamentals, Fundamentals, McGraw-Hill, 1988 McMahon, Aircraft McMahon, Aircraft Propulsion, Propulsion, Pitman, 1971 Gas Gas Turbin es: Cohen, Rogers and Saravananuttoo, Gas Saravananuttoo, Gas Turbine Theory, Theory, Longman, 1987 Mattingly, Elements of Gas Turbine Propulsion, Propulsion, McGraw Hill, 1996. Shepherd, Aerospace Shepherd, Aerospace Propulsion Propulsion, Elsevier, 1972 Rockets Hill and Peterson, Mechanics and Thermodynamics of Propulsion, Propulsion, 2nd edt, Addison Wesley, 1992. Field Field tri ps None. Ad di t io nal su bj ect co st s None.

Examination Examination material material o r equipment

1. The following scientific calculators that are not programmable, but are capable of 1-variable 1variable and 2-variabl 2-variabl e statist ics , (with the authori authori sed Faculty Faculty of Engineering Engineering o r Faculty of Science sticker ) are appro appro ved for use in this unit examination: Graphical calculators and programmable calculators are not permitted in exams. APPROVED Scien Sc ien t if i c Cal cu lat or s: Caieion: FM-83 Canon: F720, F720i Casio: fx-82, fx-83, fx-85, fx-100, fx-115, fx-115, fx-350, fx-570, fx-911, fx-911, fx-991, and fx-992 and fx3650P series Citizen: SR-135, SR-260, SR-270, SR-275 Hewlett He wlett Pa Packard: ckard: HP-6s, HP-8s, HP-9s, HP-10s, HP-30s, HP smartcalc-300s Texas Te xas ins truments: TI-30 and TI-34 series Texet: Albert 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 “ Mona Monash sh UniversityUniversityScience” Scie nce” or “ Mona Monash sh Unive University-Enginee rsity-Engineering” ring” ST STIC ICKER KER will be allowed into the examination by the invigilators.


The sticker wil l be available available from the Faculty Faculty o ffice ground floor buildin g 72. 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) 1 (1)

2 (1)

3 (2-3)

Material Some Import ant Thermodynamic s Concepts Review of first law and Gas processes Second law Isentropic efficiency Introduction to Air Breathing Breathing Engine Performance Performance Piston engine performance Turbo jet and turbo fan performance Otto and the SI Cycle Air standard cycle Stoichiometry and enthalpy of combustion Fuel-air cycle SI cycle and the Performance of real engines

4 (4)

Spark Igniti on Engines Typical engine characteristics Fuel and gas exchange processes Altitude

5 (5)

Superchargers and turb ochargers Types Performance

6 (5-6)

Propellers Propeller types and design Classical momentum theory and static performance Simple blade element and vortex theory Introduction to helicopters operation

7 (6-7)

Introduction to Gas Gas Turbines Engine Types Stagnation conditions Air standard gas gas turbine cycle Overall and system efficiencies

8 (7-10)

Gas Gas Turbines for Propuls ion I and II 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 (10-11)

Rocket propulsion Rocket propulsion systems Introduction to rocket mechanics Thrust, performance and multistaging Electric Motors

10

Chemical Rocket Motors and Nozzles Nozzles


(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/policybank/academic/education/assessment/asses sment-in-coursework-policy.html

ASSESSMENT REQUIREMENTS See At See At tac hm ent A for more details. Criteria for Marking: Marking: Marki Marki ng Scheme: 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 Development means presentation presentation of working, sketches, sketches, assumptions , figur es, explanations (etc) and where necessary necessary development o f equation s. As si gn men t su bm is si on Hard Hard Copy Submission: Assignments Submission: Assignments must include a cover sheet. The coversheet is accessible via the Monash portal page located at http://my.monash.edu.au http://my.monash.edu.au under under the heading ‘Learning and teaching tools.’ Please keep a copy of tasks completed for your records. Extensions and penalties

University and faculty poli cy on assessment ssessment 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 before the due time and date, and attach supportive evidence such as medical certificate. The form shou ld pr eferably eferably be forw arded as as an email email attachment, sent attachment, sent to the unit coordinator. The email should be sent from f rom your University email address with your name typed in lieu of signature. Note that other lecturers cannot grant extensions. Lecturer-in-charge 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. 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. 8

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 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 Friday following the submission date. Assessment for the unit unit as a whole is is in accordance accordance with the provisions provisions of the Monash Monash University Education Policy at: http://www.policy.monash.edu/pol http://www.policy.mo nash.edu/policybank/acad icybank/academic/educatio emic/education/assessment/in n/assessment/index.html dex.html

Returnin Returnin g assignments Done in the Friday Practice Class. Resubmissi Resubmissi on 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 University’s academic standards, and to provide advice on how they might uphold them. You can find Monash’s Education Policies at: www.policy.monash.ed www.policy.monash.edu.au/policy-bank/acade u.au/policy-bank/academic/education/index.html mic/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/educ http://www.policy.monash.edu /policy-bank/academic/education/management/mona ation/management/monashshgraduate-attributes-policy.html 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. 9

Student Servi Servi ces 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 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 www.lib.monash.edu.au or the library tab in my.monash my.monash portal portal for more information.

Disabilit Disabilit y 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 r egular basis. • • • •

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

Your Feedback Feedback t o 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 University’s 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 Monash’s educational strategy, see: www.monash.edu.au/about/monash-directions/directions.html and www.monash.edu.au/about/monash-directions/directions.html and on student evaluations, see: www.policy.monash.edu www.policy.monash.edu/policy-bank/academic/ed /policy-bank/academic/education/quality/student-evalu ucation/quality/student-evaluationationpolicy.html Previous Previous Student Student Evaluations Evaluations of t his 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 f or this purpose. If you wish to view how previous students rated this unit, please go to https://emuapps.monash.edu.au/unitevaluations/index.jsp


At A t t ach ac h men t A


MAE34 AE3405 Fli Fligh ghtt Vehi Vehicl cle e Pro Propul pulsi sion on 2013 Information Infor mation,, probl pr oble ems and ass assig ignments nments

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.

Unit

: MAE3405 Flight Vehicle Propulsion


Subject Coordinator : Associate Associate Professor Damon Honnery Room : Clayton G15/31 Email : [email protected] [email protected] du Details Details of thi s unit c an be found at http://www.monash.edu.au/pubs/h http://www.monash .edu.au/pubs/handbooks/un andbooks/units/MAE3405.html its/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 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. As ses sm ent : This subject will have three forms of assessment: Examination: 70% (three hours closed book). Assignments and and Laboratories: 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. At ten dance dan ce Attendance at the laboratory is compulsory. Failure to attend and submit a laboratory report may result in a fail being 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 Classes Problem solving classes are intended to assist with assignments. They will not operate in the first week of semester. semester. To benefit from these classes classes you should 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 depending on the inclination and interest of the students. As si gn ments men ts 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 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. 13

laboratory sheets. Failure to attend and submit a laboratory may result in a fail being 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 understanding of the related course material as well. See Objective section Objective section below. Submissio n Penalties 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. Ai rc raf t p erf or man ce: Anderson, Aircraft Anderson, Aircraft Performance Performance and Design, 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, Thermodynamics, Wiley, 2000 But any general thermodynamics text should be sufficient. Piston Engines Heywood, Internal Combustion Engine Fundamentals Fundamentals,, McGraw-Hill, 1988 McMahon, Aircraft McMahon, Aircraft Propulsion Propulsion, Pitman, 1971 Gas Gas Turbi nes: Cohen, Rogers and Saravananuttoo, Gas Saravananuttoo, Gas Turbine Theory, Theory, Longman, 1987 Mattingly, Elements of Gas Turbine Propulsion, Propulsion, McGraw Hill, 1996. Shepherd, Aerospace Shepherd, Aerospace Propulsion Propulsion,, Elsevier, 1972 Rockets Hill and Peterson, Mechanics and Thermodynamics of Propulsion, 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.


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 thermodynami thermodynamics cs of fuel-air power power cycles used for aircraft aircraft propulsion propulsion systems and undertake calculations of their thermodynamic thermodynamic properties. 2. Recognise the differences in real versions of of the power cycles cycles relative to their fuel-air fuel-air analogues. 3. Demonstrate knowledge knowledge of the fuels fuels used in aircraft aircraft and rocket engines engines and be able able to undertake simple combustion related calculations dealing with these fuels. 4. Understand and and undertake calculations calculations on the operation and and performance performance of piston engines, engines, turboprops, and ramjets. 5. Understand and and calculate the the effects of high speed speed flight on jets, turbofans turbofans and ramjets ramjets intakes. 6. Demonstrate knowledge knowledge of propeller propeller design design through the application application of various various blade theories. theories. 7. Understand and undertake calculations on propeller operation and performance. performanc e. 8. Understand and and undertake calculations calculations on on the operation and performance 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 requirements of of propulsion 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 Feedback (and your role role in it) Feedback on your work is provided via two methods in this unit: 3. Before handing In: 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 Handing Back: 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.


Lecture Topics and Ap proxim ate Wee Week k of DeliveryDelivery- All n otes are on Blackboard Topic (Week) 1 (1)

2 (1)

3 (2-3)

Material Some Import ant Thermodynamic s Concepts Review of first law and Gas processes Second law Isentropic efficiency Introduction to Air Breathing Breathing Engine Performance Performance Piston engine performance Turbo jet and turbo fan performance Otto and the SI Cycle Air standard cycle Stoichiometry and enthalpy of combustion Fuel-air cycle SI cycle and the Performance of real engines

4 (4)

Spark Igniti on Engines Typical engine characteristics Fuel and gas exchange processes Altitude

5 (5)

Superchargers and turb ochargers Types Performance

6 (5-6)

Propellers Propeller types and design Classical momentum theory and static performance Simple blade element and vortex theory Introduction to helicopters operation

7 (6-7)

Introduction to Gas Gas Turbines Engine Types Stagnation conditions Air standard gas gas turbine cycle Overall and system efficiencies

8 (7-10)

Gas Gas Turbines for Propuls ion I and II 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 (10-11)

Rocket propulsion Rocket propulsion systems Introduction to rocket mechanics Thrust, performance and multistaging Electric Motors

10 (11-12)

Chemical Rocket Motors and Nozzles Nozzles Supersonic propelling nozzles Chemical motor performance Design of conical nozzles Solid propellant motors


As A s s ig n men t Sub mi s si o n s Students: You must keep a copy of your assign ment •

The assignments are to be written on A4 sheets, single sided, corner stapled.

•

Do not place the assignment assignment in a folder (clear plastic or otherwise).

• An assignment assignment cover sheet is to be attached to every 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 need to check t he MAE34 MAE3405 05 Moodle Moodle page for d ata sheets sheets etc to do some of these questions.

As A s s ig n men t Ques t io n s and d ue d ates at es 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. Questio ns 2 and 4 6 and 13 18 and 24 25 and 28 30 and 33

Time and Date Due By 4:00pm in the tut e of By 4:00pm 4:00pm in the tut e of By 4:00pm 4:00pm in the tut e of By 4:00pm in the tut e of By 4:00pm in the tut e of

week 4 (23/8) (23/8) (check tut or gro up)* week 6 (6/9) (6/9) (check tut or gro up) week 8 (20/9) (20/9) (check tut or gro up) week 10 (11/10 (11/10)) (check tut or gro up) week 12 (25/10 (25/10)) (check tut or gro up)

*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 Scheme: each question will be marked as: 0/5: Not Not submitted submitted or or completely completely incorrect 1~2/5: Some attempt showing development development 2~3/5: Mostly correct, mostly developed 4~5/5: Correct with full development development Development means presentation of working, sketches, assumptions, figures, explanations (etc) (etc) and wh ere necessary necessary development of equations equations .


Question 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) t he gas constant (R kJ/kg-K) and (iii) the ratio of specific heats ( γ) (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 with constant mass flow rate of of 0.2 kg/s operates in an environment environment such that 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% N 2, 15% CO2 and 20% water (gas) by mass at 900 o 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 engine’s efficiency. Use a reference temperature of T o=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 Flight speed Mach number Intake diameter Exhaust diameter Exhaust speed Exhaust gas temperature Exhaust gas constant Fuel density

6500m 0.398 0.300m 0.285m 950kph 2500C 250J/kg-K 850kg/m3

(a) Determine the ratio of fuel mass flow to air mass mass flow for the engine. [Ans: 0.0279] (b) Calculate the net thrust developed by the engine and the thrust specific fuel consumption consumption (in kg/N.h) [Ans: 806.2 N; 0.688 kg/N-h] (c) What percentage of the gross gross thrust is used to overcome ram drag? [Ans: 46.1%] 46.1%]

Question 4 In an air standard Otto cycle the maximum and minimum temperatures are 1400 oC 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 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%]


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 cm 3 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 C nH2n+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 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

Value Quantity

IMEP Bore Stroke RPM Air to fuel ratio

1.0MPa 0.1m 0.12m 2500 14.8

Volumetric efficiency Mechanical Efficiency

78% 85%

Altitude True airspeed airspeed

3000m 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 2300 2500 2700 2900

462.135 480.838 502.890 497.984 470.747

2.311 2 .311 2.457 2 .457 2.654 2 .654 2.839 2 .839 2.966 2 .966

0.222 0.238 0.260 0.279 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. 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. 19

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 rate of 0.1 kg/s has an inlet manifold pressure 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 charge air density relative to atmospheric. 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 efficiency of the supercharger drive as 95%. [Assignment question] Questio n 14* A 2m diameter propeller propeller is being tested on the 4 cylinder cylinder SI engine whose whose data is listed below below runs on avegas. If the test is done at an altitude of 2000m, determine the static thrust developed. Assume the engine engine operates on on the fuel/air Otto cycle. cycle. [Ans: 3.25 kN] Piston Engine Quantity

Value

Value Quantity

Compression ratio Bore Stroke RPM Cp reactants Cv reactants

7.5 0.1m 0.125m 2700 1.055kJ/kg-K 0.768kJ/kg-K

Combustion efficiency Mechanical Efficiency Volumetric efficiency Air to fuel ratio Cp products Cv products

99% 85% 80% 14.5 1.486kJ/kg-K 1.199kJ/kg-K

Questio n 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 t ail 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 t hrust 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 engine are listed below. below. Quantity

Value

Value Quantity

Bore

0.1m

Combustion efficiency

98%


Stroke RPM Cylinders Fuel approximated by Cp (fuel & air) Cv (fuel & air)

0.12m 2500 6 CH2.2 1.055kJ/kg-K 0.768kJ/kg-K

Mechanical Efficiency Volumetric efficiency efficienc y Air to fuel ratio Fuel Cp (exhaust products) Cv (exhaust products)

90% 85% Stoichiometric Stoichiometric Avgas 1.486kJ/kg-K 1.199kJ/kg-K

Questio n 16* A three bladed aircraft propeller with symmetric section is to be tested at SSL conditions under zero advance speed. speed. The section lift coefficient, coefficient, angle of attack and chord are given 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] a = 0.1[1+0.1(r/R] (deg-1)

Section Lift coefficient gradient AOA as a function of of bade radius, r

= = [15-10(r/R)] (deg)

α

Chord as a function of blade radius, r

c = (R/5)[1-(r/R-0.5)2] (m)

Hub radius Blade radius

RH = 0.1R (m) 1.0m

Questio n 17* An intercooled turbocharged 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 turbocharger’s 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

Value Quantity

Compression ratio Bore Stroke RPM Cp (fuel & air) Cv (fuel & air)

7.0 0.1m 0.12m 2500 1.055kJ/kg-K 0.768kJ/kg-K

Combustion efficiency Mechanical Efficiency Volumetric efficiency Air to fuel ratio Cp (exhaust products) Cv (exhaust products)

95% 90% 100% 14.5 1.486kJ/kg-K 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 15 0 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 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(Cl0.15)2 where Cdmin=0.004+0.017(t/c). =0.004+0.017(t/c). Additional blade data from page 89 of notes. [Assignment question] Question 19 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. 21

A helicopter with with total mass 600 kg, kg, drag coefficient coefficient 0.35 and rotor diameter diameter 10 m, moves 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 Question 21 A turbojet is operating operating with the conditions conditions below. below. Quantity

Value

Value Quantity

Compressor Ratio Turbine Inlet Temp Isentropic Efficiencies Compressor Turbin Turbine e Intake Propelling Nozzle Mechanical Efficiency Combustion Efficiency Efficien cy Combustor Pressure drop

9.0 1250K 87% 87% 87% 95% 95% 99% 98% 6%

Compressor Cp Compressor γ Turbine Cp Turbine γ Exhaus Exhaustt Gas Const Constan antt R Engine Mass Flow Airspeed Altitude

1.005kJ/kgK 1.4 1.148kJ/kgK 1.333 0.287k 0.287kJ/k J/kgK gK 15kg/s 15k g/s 260m/s 7000m

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 m 2; 8.86 kN; 0.120 kg/N-h]

Question 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%]

Questio n 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 pressure ratio to be 1.3. [Ans: 1.8MW] Quantity

Value

Value Quantity

Compressor Ratio Turbine Inlet Temp Isentropic Efficiencies -Compressor -Turbine -Intake -Propelling Nozzle Spool Efficiency Combustion Efficiency Gear Box efficiency

8.0 1200K 87% 90% 93% 95% 99% 98% 90%

Combustion Pressure drop Compressor Cp Compressor γ Turbine Cp Turbine γ Exhaust Gas Constant R Intake Nozzle Area Altitude Airspeed

4% 1.005kJ/kgK 1.4 1.148kJ/kgK 1.333 0.287kJ/kgK 0.1m 2 5000m 125m/s


Questio n 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

Value Quantity

Compressor Ratio Combustor F/A ratio Isentropic Efficiencies - Compressor - Turbine and power turb. - Intake (subsonic) - Propelling nozzle Gas generator spool eff. Combustor efficiency Combustor pressure drop Propelling noz. press ratio

10 0.015 85% 90% 95% 95% 99% 98% 3% 1.2

Compressor Cp Compressor γ Turbine Cp Turbine γ Exhaust gas constant R Intake nozzle area Reheat F/A ratio Reheat comb. eff Reheat pressure drop Gear box efficiency Fuel

1.005kJ/kg-K 1.005kJ/k g-K 1.4 1.148kJ/kg-K 1.333 0.287kJ/kg-K 0.2m2 0.005 98% 2% 85% 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 Turbine Inlet Temp Fan Pressure Ratio Compressors, Fan and Turbine isentropic Eff. Intake Isentropic Eff. Propelling Nozzles Eff. Spool Mechanical Eff. Combustion Efficiency Combustion Pressure drop

20.0 1300K 1.7 90% 95% 95% 99% 98% 4%

Compressor Cp Compressor γ Turbine Cp Turbine γ Exha Exhaus ustt Gas Con Const stan antt R Airspeed Altitude Area Cold Nozzle By-pass ratio

1.005kJ/kgK 1.4 1.148kJ/kgK 1.333 0.28 0.287k 7kJ/ J/kg kgK K Mach 0.8 10,000m 0.8m 2 4

Question 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 divided into two sections: supersonic supersonic and subsonic. subsonic. In the supersonic section, 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 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. 23

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]

Questio n 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

Value Quantity

Compressor Ratio Turbine Inlet Temp Isentropic Efficiencies - Compressor - Turbine - Intake (subsonic) - Propelling nozzle Mechanical efficiency Combustor efficiency Combustor pressure drop

10 1350K 87% 87% 95% 95% 99% 98% 6%

Compressor Cp Compressor γ Turbine Cp Turbine γ Exhaust gas constant R Engine air mass flow After burner efficiency Afterburner temperature Afterburner pressure drop

1.005kJ/kg-K 1.005kJ/k g-K 1.4 1.148kJ/kg-K 1.333 0.287kJ/kg-K 20kg/s 95% 2000K 5%

Question 29 A single stage rocket is being designed to launch a satellite. The launch angle of 80 0 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 0.1m 2, 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/O 2 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 m 3; (ii) 6095 kg; 23175 m 3] (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 ] Questio n 30* A single stage rocket is used to launch a satellite. A launch angle of 85 0 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 2750 oC. A convergent/divergent convergent/divergent nozzle is used with throat area 0.1m 2. 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 (i) the launch thrust at SSL; and (ii) the (ii) the motor burnout height assuming the nozzle exit velocity remains constant at its launch value. [Assignment question] 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. 24

Question 31 A rocket is being designed to launch launch a deep space space probe. The total mass of the rocket is limited 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 payload and total propellant mass if the rocket is made up of either (i) 1 or (ii) 2 stages. [Ans: (i) 8 kg; 917kg; 917kg; (ii) 45 kg; 864 kg] 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 0.1m 2. 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=0.1m 2. Solution of this problem will require numerical integration of the force balance over a small time interval until the total propellant mass is consumed. Questio n 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 –23 oC, 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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