Study-Unit Description

Study-Unit Description


TITLE Compressible Aerodynamics and Propulsion Theory for Aerospace

LEVEL 04 - Years 4, 5 in Modular UG or PG Cert Course


DEPARTMENT Mechanical Engineering

DESCRIPTION The study-unit is particularly focused on the science that underpins the aerodyanmic and propulsion methods used and applied in aerospace application. In particular fundamental compressible flow behaviour is introduced and developed in some detail. The fundamentals then serve as a basis to analyse and characterise extensively the compressible aerodynamics round various aerospace fluid systems.

Study-unit Aims:

- Introduce fundamentals of compressible fluid dynamics e.g. speed of sound, definition of subsonic, sonic, supersonic flow and other critical conditions;
- Introduce the conservation laws (mass, momentum, energy, thermodynamic laws) and constitutive equations (equations of state) using a compressible framework;
- Describe the concept of stagnation and its impact on various fluid domain variables;
- Analyse isentropic flows;
- Analyse Fanno Flow;
- Analyse Rayleigh Flow;
- Analyse Mass addition flow in compressible flow framework;
- Introduce influence coefficients;
- Introduce the civil turbofan architecture;
- Introduce the two methods of creating thrust and the preference for large bypass ratios;
- Introduce dimensional analysis and scaling and its importance for off-design matching.

Learning Outcomes:

1. Knowledge & Understanding
By the end of the study-unit the student will be able to:

- Identify the conditions and different characteristics of compressible flow;
- Identify the key analytical differences from incompressible flow to characterize compressible flows in various governing flow models e.g. Euler Equations, Bernouilli's equation and Navier Stokes Equations;
- Correlate the relationship between entropy change and enthalpy;
- Define stagnation conditions for temperature, pressure and enthalpy;
- Define the various characteristics of the shock wave;
- Characterise the creation and derivatives of of thrust in an axial flow gas turbine;
- Analyse compressor and turbine behaviour using compressible turbomachinery thermodynamic principles.

2. Skills
By the end of the study-unit the student will be able to:

- Apply compressibility concepts to isentropic applications e.g. flow past turbine blades, jet engine diffuser intake, nozzles in a rocket;
- Analyse choked flow in a converging and diverging nozzle;
- Apply compressibility concepts to diffuser and converging-diverging nozzle applications;
- Interpret a T-S diagram;
- Identify the various components of a jet engine and their function in the creation of thrust;
- Interpret flow fields round transonic and supersonic airfoils;
- Correlate the thermodynamic behaviour of jet engine components to a T-S diagram;
- Carry out a performance and an engine matching off-design analysis.

Main Text/s and any supplementary readings:

- Fundamentals of Compressible Fluid Dynamics – 2006 by P. Balachandran ISBN 9788120328570.
- Jet Propulsion - A simple guide to the aerodynamic and thermodynamic design and performance of jet engines - Second Edition - 2007 - by Nicholas Cumpsty ISBN 9780521541442.
- Fluid Mechanics - Eighth Edition - 2016 - by Frank White ISBN 978-0073398273.

ADDITIONAL NOTES Pre-Requisite Study-unit: MEC3108

STUDY-UNIT TYPE Lecture and Tutorial

Assessment Component/s Assessment Due Resit Availability Weighting
Presentation SEM1 No 5%
Assignment SEM1 No 10%
Online Examination (3 Hours) SEM1 Yes 85%

LECTURER/S Simon Mizzi

The University makes every effort to ensure that the published Courses Plans, Programmes of Study and Study-Unit information are complete and up-to-date at the time of publication. The University reserves the right to make changes in case errors are detected after publication.
The availability of optional units may be subject to timetabling constraints.
Units not attracting a sufficient number of registrations may be withdrawn without notice.
It should be noted that all the information in the description above applies to study-units available during the academic year 2020/1. It may be subject to change in subsequent years.