Aerospace Propulsion

Aerospace Propulsion

AERE-411

Previous offerings

Fall 2023, F'22, F'17, F '16, Sp '16, F '15, F '14, F '13

Course Objectives

Aerospace vehicles (aircraft, helicopters, rockets, etc.) all require some means to propel them forward. All of these rely on Newton’s third law to achieve propulsion . . . push something (typically air) back to get forward momentum increase. Propulsion devices can be categorized as air-breathing engines and rocket engines. Air-breathing propulsion, of course, is limited to operation within the earth’s atmosphere but is much more efficient. Most aircraft and helicopters, therefore, rely on air-breathing propulsors (typically gas turbines). A majority of the course will, therefore, focus on gas turbines. This course will provide fundamental principles of gas turbine and rocket engines. Basic aero-thermodynamic performance analysis of such propulsors, as well as their individual components, will be taught. Such analysis, called “cycle” analysis will be covered for both ideal- as well as non-ideal performance. How the different components of a gas turbine work together to provide propulsion will be discussed. Most of the focus will be on design operation; off-design analysis will only be touched upon.

Outcomes

On completion of the course the attentive student will understand:

• The basic principles of aircraft propulsion devices (propulsors)
• Rockets and ramjet principles
• How to perform ideal, non-ideal, and off-design “cycle” (thermodynamic) analysis of propulsors
• How to analyze the performance of various components of a jet engine: inlet, compressor, combustor, turbine, and nozzle

Syllabus

• Review of Thermodynamics and gas dynamics
• Engine component analyses: inlet, compressor, combustor, turbine, nozzle
• Ideal cycle analysis
• Turbojet
• Ramjet
• Afterburning turbojet
• Turbofans - separate and mixed streams
• Basic rocket analysis
• Non-ideal cycle analysis
• Off-design analysis
• Special topics (time permitting)

Textbook and reading mtl.

The suggested reading materials include the following.

• Oates, G. C. (1997). Aerothermodynamics of gas turbine and rocket propulsion (3rd ed.). AIAA. (textbook: not required)
• Cumpsty, N. A. (2003). Jet Propulsion: A simple guide to the aerodynamic and thermodynamic design and performance of jet engines (Second). Cambridge University Press.
• Mattingly, J. D., & von Ohain, H. (1996). Elements of gas turbine propulsion. McGraw-Hill New York.
• Hill, P. G., & Peterson, C. R. (1992). Mechanics and thermodynamics of propulsion. Addison-Wesley Publishing Co.
• Farokhi, S. (2021). Aircraft Propulsion: Cleaner, Leaner, and Greener. John Wiley & Sons.

Lecture videos

• Week 1
  • Lecture 1. Introduction and logistics; Newton’s laws and propulsion systems
  • Lecture 2. The “gas generator” and its variants; thermodynamic cycles; how to select a propulsor
  • Lecture 3. Revision of Thermodynamics: 1st law; example problems
• Week 2
  • Lecture 4. Thermodynamics: example problems
  • Lecture 5. Reynolds transport theorem; conservation laws - mass and momentum
  • Lecture 6. Conservation of energy; Quasi-1D flow
• Week 3
  • Lecture 7. No class
  • Lecture 8. Components in a GT; Ideal and real inlet/diffuser
  • Lecture 9. GT components: Ideal/real compressor; ideal/real combustor and pressure loss
• Week 4
  • Lecture 10. No class; quiz/assessment in class
  • Lecture 11. R-L flow review; total pressure loss in R-L flow; example problem
  • Lecture 12. Ideal turbojet; engine thrust; solution strategy
• Week 5
  • Lecture 13. Ideal turbojet - specific thrust, T-S map
  • Lecture 14. Ideal turbojet - solution strategy; power balance
  • Lecture 15. Max thrust turbojet; solution properties
• Week 6
  • Lecture 16. Ideal turbojet example problem
  • Lecture 17. Ramjet with a compressor
  • Lecture 18. Rocket engines - review of Quasi-1D nozzle flow
• Week 7
  • Lecture 19. Rocket engines - thrust, Cf; variable-geometry nozzles; Summerfield criterion
  • Lecture 20. Rocket engines - example problems
  • Lecture 21. Rocket engines - example problems continued
• Week 8
  • Lecture 22. Afterburning turbojet
  • Lecture 23. No class. In-class quiz.
  • Lecture 24. Afterburning turbojet example problem
• Week 9
  • Lecture 26. Off-design analysis - area scheduling
  • Lecture 27. Review for the midterm
  • Lecture 28. No class. Mid-term exam.
• Week 10
  • Lecture 29. Component matching (nozzle and turbine)
  • Lecture 30. Compressor map; operating line; example problem
  • Lecture 31. No class.
• Week 11
  • Lecture 31. Ideal turbofan engines - engines for Boeing 777; separate stream turbofan; T-S maps
  • Lecture 32. Separate stream turbofan - example problem
  • Lecture 33. Separate stream turbofan - more examples
• Week 12
  • Lecture 34. Separate stream turbofan - more examples
  • Lecture 35. Mixed stream turbofan; advantages of mixing
  • Lecture 37. No class. In-class quiz.
• Week 13
  • Lecture 37. Mixed stream turbofan example problems
  • Lecture 38. Non-ideal analysis - diffusers
  • Lecture 39. Non-ideal compression; adiabatic/isentropic and polytropic efficiencies
• Week 14
  • Lecture 40. Non-ideal burning and expansion; efficiencies
  • Lecture 41. Non-ideal expansion; total-to-total and total-to-static efficiencies; why use diffusers in power generation machines
  • Lecture 42. No class. In-class quiz.
• Week 15
  • Lecture 43. Example problems - efficiencies
  • Lecture 44. Review - 1
  • Lecture 45. Review - 2. Not recorded.