AIRCRAFT PROPULSION
Course Objective:
The main objective of this course is to provide fundamental knowledge and skills to Aircraft Propulsion. After completion of this course the students will be able to know in depth knowledge of design process of Propulsion systems.
 Introduction (4 hours)
 Brayton Cycle
 Types of Jet Engine
 Components of Jet Engine
 Basics of Total and Static Enthalpies
 Thrust Equations and Propulsive Efficiencies
 Fundamentals of Thermal Turbomachines (8 hours)
 Review on Compressible Aerodynamics
 Turbomachine System Discretization
 Fundamental Equations
 Conservation of Mass
 Conservation of Energy
 Conservation of Momentum
 Euler's Turbine Equation
 Rothalpy
 Efficiencies
 Isentropic Efficiency
 Calculating with Isentropic Efficiencies
 Polytropic Efficiency
 Combustion Chambers and Nozzles (8 hours)
 Classification of combustion chambers
 Important factors affecting combustion chamber design
 Combustion process
 Combustion chamber performance
 Effect of operating variables on performance
 Flame tube cooling
 Flame stabilization
 Use of flame holders
 Theory of flow in isentropic nozzles
 Convergent nozzles and nozzle choking
 Nozzle throat conditions
 Nozzle efficiency
 Losses in nozzles
 Over expanded and under Expanded nozzles
 Ejector and variable area nozzles
 Interaction of nozzle flow with adjacent surfaces
 Compressors (14 hours)
 Types of Compressors
 Stage Velocity Triangle
 First Design Parameter: Degree of Reaction
 Second Design Parameter: Loading Factor
 Third Design Parameter: Flow Coefficient
 The Normalized Velocity Triangle
 Special Cases
 Degree of Reaction equal to one half (R = 0.5)
 Zero Exit Swirl (Cθ,3 = 0)
 Simplified OffDesign Analysis
 Axial Compressor  Effect of Degree of Reaction
 Compressor Design Aspects
 Axial Compressor Rotor Types
 Multiple Rotors
 Rotor Blade Mount
 Stator Vane Mount
 Variable Stage Geometry
 Surge Control (Bleed Valve)
 Boundary Layer Control
 Aspiration
 Blade Twist
 Turbines (12 hours)
 Types of Turbine
 Stage Velocity Triangles
 First Design Parameter: Degree of Reaction
 Second Design Parameters: Loading Factor
 Third Design Parameters: Flow Coefficient
 The Normalized Velocity Triangle
 Special Cases
 Degree of Reaction Equal to Zero (R = 0; Action Turbine)
 Degree of Reaction equal to one half (R = 0.5; Reaction Turbine)
 Zero Exit Swirl (Cθ,3 = 0)
 Axial Turbine  Effects of Degree of Reaction
 Turbine Design Aspects
 Disk Rotor
 Drum Rotor
 Sealing Aspects
 Action Turbine
 Reaction Turbine
 Turbine Blade Geometry
 ThreeDimensional Effects
 Design of Multistage Turbine
 System Discretization
 Problem Statement
 Determination of Approximate Flow Parameters
 Determination of Inlet and Outlet Angular Geometry
 Determination of Number of Stages
 Determination of Stage Efficiency
 First Iteration of Flow Parameters
 Finalization of First Iteration
 Losses in Turbomachines (4 hours)
 Losses
 Losses in a Turbine Stage
 Loss Coefficients
 Dependency of the Efficiency from Design Parameters
 Reaction Turbine (R = 0.5)
 Action Turbine (R = 0)
 Propulsion (10 hours)
 Turbine Engines
 Construction Arrangement and operation of turbojet, turbofan, turboshaft and turbopropeller engines.
 Electronic Engine Control and Fuel Metering Systems (FADEC)
 Engine Indicating Systems (EICAS/ECAM)
 EGT/ITT
 Engine Speed
 Engine Thrust Indication
 Oil Pressure and Temperature
 Fuel Pressure, Temperature and Flow
 Manifold Pressure, Engine Torque and Propeller Speed
 Starting and Ignition System
 Operation of Engine Start Systems and Components
 Ignition Systems and Components
 Maintenance Safety Requirements
References
 Dixon, S.L., 1998 "Fluid Mechanics and Thermodynamics of Turbomachinery" 4th Edn. ButterworthHeinemann, Woburn, MA, USA, 1998 (ISBN 0750670592)
 Soderberg, C.R., 1949 Unpublished Note, Gas Turbine Laboratory, Massachusetts Institute of Technology
 Hill, P.G. & Peterson, C.R. “Mechanics & Thermodynamics of Propulsion” Addison – Wesley Longman INC, 1999.
 Cohen, H. Rogers, G.F.C. and Saravanamuttoo, H.I.H. “Gas Turbine Theory”, Longman, 1989.
 Oates, G.C., “Aero thermodynamics of Aircraft Engine Components”, AIAA Education Series, New York, 1985.
 “Rolls Royce Jet Engine” – Third Edition – 1983.
 Mathur, M.L. and Sharma, R.P., “Gas Turbine, Jet and Rocket Propulsion”, Standard Publishers &Distributors, Delhi, 1999.
 Sutton, G.P., “Rocket Propulsion Elements”, John Wiley & Sons Inc., New York, 5th Edn., 1993.
 http://web.mit.edu/16.unified/www/SPRING/propulsion/notes/node70.html
 FAA Aircraft Propulsion 12A and 15A
Project
1. Simulation of Axial Compressor or Turbine in available CFD Software. Details of Project:
Euler's Radius =
Pressure Ratio of a stage =
Mass Flow Rate (kg/s) = (Through a sector)
Thermal Head (J) = (Total quantity)
Density of gas (kg/m3) = S (average value in that sector)
Stage Inlet Temperature (K) =
Stage Pressure at Inlet =
Tip Clearance= (% of blade span)
Hint:
 Use Euler's Turbine Equation to find the LE and TE stagger angle.
 Approximate a curve tangential to these curves found in step 1.
 Use appropriate airfoil/thickness ratio for 2D design.
 Develop 3D design from data and above steps.
 Carry out CFD simulation for the given conditions
Note: Assume appropriate data if missing.
Evaluation Scheme:
The questions will cover all the chapters of the syllabus. The evaluation scheme will be as indicated in the table below:
Unit 
Chapter 
Topics 
Marks 
1 
1 & 3 
All 
16 
2 
4 
All 
16 
3 
5 
All 
16 
4 
2 & 6 
All 
16 
5 
7 
All 
16 
Total 
80 
*Note: There may be minor deviation in marks distribution
