LEARNING OUTCOMES

The module aims at providing the fundamentals for the study of the systems for aeronautical propulsion, particularly addressing the following topics: thrust and performance of different types of engines in different flight phases, engine layouts and main components responsible for propulsion.

AIMS AND LEARNING OUTCOMES

The active participation into classroom lessons and the personal study allow the student:

- to distinguish the different types of aeronautical engines and to understand the mode of operation;  

- to evaluate the aircraft requirements during the different flight phases;

- to select the proper engine to satisfy the specific requirements;

- to understand the mechanisms of thrust generation for the different kinds of engine;

- to evaluate the performance of a propulsion system;

- to identify the design parameters, which drive the thrust generation and influence the propulsion  system performance;

- to know and understand the operation mode of the main components of the engine responsible for the thrust generation.

TEACHING METHODS

The module is articulated into classroom frontal lessons, which foresee not only presentation and discussion of the theoretical contents, but also some numerical applications aimed at promoting learning and comprehension.

SYLLABUS/CONTENT

The main contents of the module are here listed:

- Brief introduction to the aeronautical propulsion history; large aircraft propulsion; standard atmosphere; units used in the aeronautical field.

- Classification of the aeroengines: architectures of propeller engines, ramjet, turbojet with and without afterburner, turbofan with low and high by-pass-ratios, pulsejet.

- Aircraft aerodynamics principles: lift, drag and momentum coefficients; finite wings and induced drag; wing aspect ratio.

- Airplane drag polar; aerodynamic forces acting on the airplane; thrust and power required for level, unaccelerated flight; maximum velocity; rate of climb; gliding flight; absolute and service ceiling; time-to-climb. Range and endurance for propeller driven and jet airplanes. Breguet’s range formula. Takeoff and landing performance. Turning flight and the v-n diagram. 

- Evaluation of the engine requirements, installed and uninstalled thrust.

- Generation of thrust for turbojet, turbofan, and turboprop. Actuator disk and blade element theories. Performance parameters of propulsion systems: cycle efficiency, propulsion efficiency, and overall efficiency.

- Turbojet engine: cycle analysis, design paramaters.

- Turbofan engine: cycle analysis, by-pass ratio selection.

- Turboprop engine: cycle analysis, optimum power split between the propeller and the jet.

- Main components responsible for the propulsion. Inlets: main requirements, non-dimensional parameters, diffuser geometries, Sovran and Klomp diffuser performance charts, supersonic inlets. Nozzles: main requirements, performance, nozzle area scheduling. Thrust reverser and thrust vectoring.                                                                 

RECOMMENDED READING/BIBLIOGRAPHY

Lesson notes and classroom material are sufficient for the exam preparation.

The books here listed are also suggested as a support:

- J. D. Anderson, “Introduction to Flight, Sixth Edition”, McGraw-Hill

- S.  Farokhi, “Aircraft Propulsion”, John Wiley & Sons

- N. Cumpsty, “Jet Propulsion”, Cambridge University Press

- R. D. Flack, “Fundamentals of Jet Propulsion with Applications”, Cambridge University Press