93754 - Principles Of Aerospace Propulsion

Learning outcomes

The integrated course Fundamentals of Aerospace Engineering introduces the student to the principles that govern the design and operation of aerospace vehicles. The student develops a multidisciplinary understanding of the main areas of aerospace engineering — aerodynamics, propulsion, structures, and flight mechanics — learning how aerodynamic, structural, and performance aspects interact in defining an aircraft configuration. In this module, the student acquires fundamental knowledge of thrust generation and of the main aerospace propulsion systems. The course provides an overview of air-breathing and rocket engines, their operating principles, performance characteristics, and typical fields of application.

Course contents

Introduction
Thrust, power, propulsion efficiency. Evaluation with respect the ratio between the vehicle speed and the gas speed exiting the engine.

Gas turbine engines
Introduction to the main gas turbine engine architectures: turbojet, turbofan and turboprop.
Thrust for airbreathing engines. By-pass ratio. Thrust for engines with high by-pass ratio.
Thermodynamic, propulsion and total efficiencies. Take off thrust and maximum range. Performance, Thrust Specific Fuel Consumption: typical values for ramjet, turbojet, turbofan and turboprop.
Thermodynamics of gas turbine: Optimization of the Brayton cycle, compression ratio variation effects on efficiency and specific work produced, maximum cycle temperature influence on cycle efficiency. Isentropic and polytropic efficiencies for compression and expansion.
Gas turbine engines static components: Intake (sub-sonic and super-sonic), nozzle, combustion chamber.

Rockets
Rocket propulsion introduction. Chemical rockets configurations: liquid and solid propellants.

Readings/Bibliography

Sutton - Rocket Propulsion - John Wiley & Sons, New York

Hill & Peterson - Mechanics and Thermodynamics of Propulsion -Addison-Wesley Publishing Company - New York

Teaching methods

The lessons are blended with some students in classroom and others on-line. All the information and the material that is needed in order to successfully pass the exam are presented by the teacher at the board.

Attendance is strongly recommended for an improved learning of concepts and notions, but does not affect the final evaluation process.

Assessment methods

Final exam will be a discussion during which students will be asked theoretical questions about the subjects explained during the course.

In the course of the examination it will be also assessed student's ability to resolve new problems or at least to set up the correct resolutive strategy.

The evaluation, expressed in thirtieths, will be higher the more the student is:

• autonomous in articulating responses to the two questions;
• exhaustive in explaining the arguments;
• precise in representing the functionality of the free-hand sketches.

Teaching tools

Teacher's notes are available onVirtuale

Office hours

See the website of Fabrizio Ponti