Propulsion Systems

General characterization

Prerequisites

Background in thermodynamics, fluid mechanics, and heat transfer at a fundamental level is recommended but not mandatory.

Bibliography

• Saeed Farokhi, “Aircraft propulsion: cleaner, learner, and greener”. John Wiley & Sons, 3^rd edition, 2022. 
• Ahmed F. El-Sayed, “Aircraft propulsion and gas turbine engines”, 2^ndedition, 2017.
• Ahmed F. El-Sayed, “Fundamentals of aircraft and rocket propulsion”. Springer, 1^st edition, 2016.
• George P. Sutton and Oscar Biblarz, “Rocket propulsion elements”. John Wiley & Sons, 9^th edition, 2016. 
• Rolls Royce, “The jet engine”, Wiley, 5^th Edition, 2015.
• Frank M. White and Henry Xue, “Fluid eechanics”. McGraw-Hill, 9^th Edition, 2021.
• Michael J. Moran and Howard N. Shapiro, "Fundamentals of engineering thermodynamics", John Wiley & Sons, 5^th edition, 2006.
• Stephen R. Turns, “An introduction to combustion”, McGraw-Hill, 3rd Edition, 2012.

Teaching method

The presentation of the syllabus of the curricular unit is done in theoretical-practical classes. After exposing the theoretical concepts, the professor proposes to the students the resolution and subsequent discussion of practical application problems. In addition to the theoretical-practical classes, students (organized into groups) carry out a comprehensive literature investigation (with ensuing presentation and discussion) on specific and promising concepts on sustainable aircraft propulsion. 

Evaluation method

The assessment in this curricular unit takes into account the following:

• 2 tests or 1 final exam; and
• 2 assignments.

The final mark calculation (FM) is given by the following equation which involve the mark of Test 1 (MT1), mark of Test 2 (MT2), mark of the Final Exam (MFE), and the marks of the Assignments (MA1 and MA2) — the values are rounded to one decimal place:

FM = MAX{0.40(MT1+MT2);  0.80MFE} + 0.10(MA1+MA2)

To be approved at this curricular unit the student must verify the following criteria:

• obtain a classification for each assignment (MA1 and MA2) ≥ 8.0 pts (Frequency);
• obtain a final mark (FM) ≥ 9.5 pts.

Final marks higher or equal to 17 pts can be subjected to an oral examination.

Additional information and general rules for written evaluations:

• Written evaluation (tests and exams) are closed book. Any formulae, chart, or table required will be provided at the evaluation statement.
• During the evaluation it is strictly forbidden the utilization of: (1) calculators with text storage capacity; (2) smartphones; (3) smartwatches; (4) any mean or device that allows data storage; (5) any mean or device that allows communication with other person or resource inside or outside the room where the evaluation is conducted. Transgressions are subjected to the RAC.
• Only pen-answered questions are accepted. 
• Students should make use of a classic watch (watch without any data storage capacity) to control the available time.
• Students must register for the tests and exams during the corresponding time frames.

Subject matter

1. Introduction to aircraft propulsion. Definition and classification of aircraft and propulsion systems; brief and early history of aviation and aircraft propulsion; innovative breakthroughs in gas turbine propulsion; aviation impact on the environment and sustainable aviation.
2. Compressible flow. Revision of thermodynamics; speed of sound; adiabatic and isentropic steady flow; isentropic quasi-one-dimensional flow; normal shock wave; oblique shock wave; conical shocks; Prandtl-Meyer expansion waves; fluid impulse.
3. Thermochemistry and chemical kinetics. Laws governing mixture of gases; chemical reaction and flame temperature; chemical equilibrium and chemical composition; chemical kinetics.
4. Engine thrust and performance parameters. Rigorous derivations of uninstalled thrust and installation effects; airbreathing engine performance parameters: specific thrust, specific fuel consumption and impulse, thermal, propulsive and overall efficiency, and impact of engine overall efficiency on aircraft range and endurance; performance characteristics of modern aircraft engines.
5. Analysis of aircraft gas turbine engine cycles. Turbojet engine; turbojet engine with an afterburner; turbofan engine; ultra-high bypass turbofan engine with an afterburner; separate-exhaust and mixed-exhaust turbofan engines; and turboprop engines; propeller theory (actuator disk); description of real and ideal behaviors of engine components; physical and mathematical definition of efficiencies, losses, and other performance parameters for each engine component; calculation of engine performance parameters, viz. specific thrust, specific fuel consumption and thermal, propulsive, and overall efficiencies; promising propulsion and power technologies in sustainable aviation.
6. Rocket and hypersonic propulsion. Chemical rockets: liquid, solid, gaseous, and hybrid propellant rockets. Chemical rocket applications. Rocket propulsion parameters, thrust coefficient, characteristic velocity, propulsive and overall efficiency.

Programs

Programs where the course is taught: