18AE43 Aircraft Propulsion syllabus for AE

Introduction:

Review of thermodynamic principles, Principles of aircraft propulsion, Types of power plants, Working principles of internal combustion engine, Two – stroke and four – stroke piston engines, Gas- turbine engines, Cycle analysis of reciprocating engines and jet engines , advantages and disadvantages.

Propeller Theories & Jet propulsion

Types of propeller, Propeller thrust: momentum theory, Blade element theories, propeller blade design, propeller selection.

Jet Propulsion:

Illustration of working of gas turbine engine – The thrust equation – Factors affecting thrust – Effect of pressure, velocity and temperature changes of air entering compressor – Methods of thrust augmentation – Characteristics of turboprop, turbofan and turbojet – Performance characteristics.

Inlets & Nozzles

Internal flow and Stall in Subsonic inlets, Boundary layer separation. Major features of external flow near a subsonic inlet. Relation between minimum area ratio and eternal deceleration ratio. Diffuser performance.

Supersonic inlets:

Supersonic inlets, starting problem in supersonic inlets, Shock swallowing by area variation, External deceleration. Modes of inlet operation.

Nozzles:

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, Thrust reversal.

Gas Turbine Engine Compressors

Centrifugal compressors:

Principle of operation of centrifugal compressors. Work done and pressure rise - Velocity diagrams, Diffuser vane design considerations. performance characteristics. Concept of Pre-whirl, Rotating stall.

Axial flow compressors:

Elementary theory of axial flow compressor, Velocity triangles, Degree of reaction, three-dimensional flow. Air angle distribution for free vortex and constant reaction designs, Compressor blade design. Axial compressor performance characteristics.

Combustion chambers and Turbines

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

Axial Flow Turbines:

Introduction, Turbine stage, Multi-staging of turbine, Exit flow conditions, Turbine cooling, Heat transfer in turbine cooling.

Radial turbine:

Introduction, Thermodynamics of radial turbines, Losses and efficiency.

Course Outcomes:

At the end of the course the student will be able to:

1. CO1: Apply the basic principle and theory of aircraft propulsion.

2. CO2 : Explain the functions of centrifugal, axial compressors, axial and radial turbines

3. CO3: Analyse the performance of nozzles & inlets and combustion chamber.

Question paper pattern:

• The question paper will have ten full questions carrying equal marks. Each full question consisting of 20 marks.
• There will be two full questions (with a maximum of four sub questions) from each module.
• Each full question will have sub question covering all the topics under a module.
• The students will have to answer five full questions, selecting one full question from each module.

Textbook/s

1 Aircraft propulsion Bhaskar Roy Elsevier 2011

2 Gas Turbines V. Ganesan Tata McGraw-Hill 2010

Reference Books

1 Mechanics & Thermodynamics of Propulsion Hill, P.G. & Peterson, C.R Addison – Wesley Longman INC, 1999

2 Gas Turbine Theory Cohen, H. Rogers, G.F.C. and Saravanamuttoo, H.I.H Longman 1989

3 Gas Turbine Engine Technology Irwin E. Treager Tata McGraw Hill Publishing Co. Ltd. 7th Edition,2003

4 Fundamentals of Compressible Flow with Aircraft and Rocket propulsion S. M. Yahya New Age International Publications, New Delhi 4th Edition,2014

5 Aerodynamics Clancy L. J. Sterling book house, New Delhi 2006