Aerodynamics of Compressors and Turbines (AE 651) Autumn Semester - PowerPoint PPT Presentation

Aerodynamics of Compressors and Turbines (AE 651) Autumn Semester 2009 Instructor : Bhaskar Roy Professor, Aerospace Engineering Departm ent I .I .T., Bom bay e-m ail : aeroyia@aero.iitb.ac.in

AE 651 Elective Course : Ph.D / M.Tech / D.D / B.Tech The coverage in this course will be with reference to their application in Aerospace engineering and specifically with reference to Compressors and Turbines as used in Aircraft Gas Turbine engines. They are also relevant to Compressors and Turbines used in land based thermal power generation power plants . AE 651- Prof Bhaskar Roy, IITB Lect - 1

Coverage 1. Axial Flow Compressors 2. Centrifugal Flow Compressors 3. Axial Flow Turbines 4. Radial Flow Turbines 5. Matching of Compressors & Turbines 6. Mathematical models for 3-D flow in turbomachinery 7. CFD methods for flow analysis in compressors and turbines 1 AE 651- Prof Bhaskar Roy, IITB Lect-1

References 1. Hill Philip, Peterson Carl, Mechanics and Thermodynamics of Propulsion , 2nd Edn., Addison Wesly, 1992. 2. El-Sayeed G Ahmed, Aircraft Propulsion and gas Turbine Engines, CRC press, 2008. 3. Saravanamuttoo, H.I.H., Rogers G.F.C., Cohen H. Gas Turbine Theory, 5th Edition, Pearson, 2001. 4. Bhaskar Roy, Aircraft Propulsion, Elsevier, 2008 2 AE 651- Prof Bhaskar Roy, IITB Lect-1

CDEEP Date-wise schedule : Course Details AE 651 Aerodynamics of Compressors and Turbines Prof. Bhaskar Roy 3 AE 651- Prof Bhaskar Roy, IITB Lect - 1

Course Details – AE 651 No . Date Lecture /. Topic Tutorial No 1. 23.07.09 Lect-1 Course Coverage, Introduction to Aerodynamic Machines 2. 27.07.09 Lect-2 Ch-1, Introduction to Axial Flow Compressors 3. 30.07.09 Lect-3 Ch-1, Thermodynamics of Axial Flow Compressor 4. 03.08.09 Lect- 4 Ch-1, 2-D cascade flow theory of Axial Flow Compressor 5. 06.08.09 Tute-1 Quiz and Assignment - Aerothermodynamics of Axial Flow Compressor 6. 10.08.09 Lect-5 Ch-1, 3-D flows in AFC –Vortex theories 7. 13.08.09 Lect-6 Ch-1, Losses and Efficiencies of AFC 8. 17.08.09 Tute-2 Quiz and Assignment - 3-D flows and efficiencies 9. 20.08.09 Lect-7 Ch-1, Characteristics of Single and Multi-stage Compressors 10. 24.08.09 Lect-8 Ch-1, Aerodynamic design of Axial Flow Compressor 4

Course Details – AE 651 No. Date Lecture /. Topic Tutorial No 11. 27.08.09 Lect-9 Ch-2, Aerodynamics of Centrifugal Compressors 12. 31.08.09 Lect-10 Ch-2, Characteristics of Centrifugal Compressors 14. 03.09.09 Tute-3 Quiz and assignment on Centrifugal Compressor . 15. 17.09.09 Lect-11 Ch-3, Introduction and 2-D theories of Axial Flow Turbine 16. 24.09.09 Lect-12 Ch-3, Thermodynamics, Losses & Efficiencies of AFT 17. 01.10.09 Lect-13 Ch-3, Characteristics of Single & Multi-stage AFT 18. 05.10.09 Tute-4 Quiz and Assignments on Axial Flow Turbines 19. 08.10.09 Lect-14 Ch3, Cooling Techniques used in AFT 20. 12.08.09 Lect-15 Ch3, Aerodynamics Design of AFT 5

Course Details – AE 651 No . Date Lecture /. Topic Tutorial No 21. 15.10.09 Lect-16 Ch 4, Aerodynamics of Radial Flow Turbines 22. 22.10.09 Tute- 5 Quiz and Assignment on RFT 23. 26.10.09 Lect-17 Ch-5, Matching of Compressors and Turbines 24. 29.10.09 Lect-18 Ch-6, Aerodynamic Analysis of Compressors & Turbines – 3-D flow theories 25. 05.11.09 Lect-19 Ch-6,Aerodynamic Analysis of Compressors & Turbines – Radial Equilibrium Equation and Streamline Curvature Theories. 26. 09.11.09 Lect-20 Ch-7,Computational Techniques and CFD tools 27. 12.11.09 Lect-21 Ch-7, Examples of CFD analysis of Compressor and Turbine flows 6

Gas Turbine Engine LP LP Fan HP Turbine Compressor LP Turbine Compressor HP Hot Compressor Jet Inner Shaft Outer shaft carrying LPT, carrying LPC and Fan HPT and HPC 7 AE 651- Prof Bhaskar Roy, IITB Lect-1

Aerodynamic Machines • All the above machines work on various Aerodynamic principles and laws • They also have to conform to various Laws of Motion (e.g. Newton’s laws) • All these machines also need to conform to laws of thermodynamics, especially when they are part of a heat engine e.g. Gas Turbine Engine for aircraft propulsion 8 AE 651- Prof Bhaskar Roy, IITB Lect-1

Laws of Motion • 1 st Law of Motion – Concept of applying energy or force on fluid flow • 2 nd Law of Motion – Concept of acceleration (or deceleration) of fluid • 3 rd Law of motion – Concept of Reaction force due to application of a force, due to acceleration 9 AE 651- Prof Bhaskar Roy, IITB Lect-1

Laws of Thermodynamics • 1 st Law of Thermodynamics – Equality of supplied energy and work done – brings in the concept of Cycle - in flowing fluid • 2 nd Law of Thermodynamics – Concept of Entropy, and change of entropy, ∆ s • 3 rd Law of Thermodynamics – Concept of absolute zero temperature (Temp in K) • Concept of Static and Stagnation (Total) Pressure (p , p 0 ) and Temperature (T, T 0 ) • Equation of state p = ρ RT assumed valid 10 AE 651- Prof Bhaskar Roy, IITB Lect-1

Aerodynamic Laws • Newtonian fluid – continuum theory is valid • Conservation of mass in a fluid flow – Continuity equation • Conservation of momentum in a fluid flow – Euler’s equation • Conservation of energy in a fluid flow – Bernoulli’s equation – incompressible flow and ideal fluid p 0 = p + 1/2 .ρ. V 2 Navier-Stoke’s equation – real fluid for both incompressible and compressible flows 11 AE 651- Prof Bhaskar Roy, IITB Lect-1

Aerodynamic Principles • Perfect gas/air, Ideal fluid – Isentropic – adiabatic, irreversible fluid flow process • Effects of Mach number, Reynolds number etc. shall be made liberally • More parameters for dynamical similarity shall be developed for compressors / turbines • Incompressible and Compressible fluid flow • Subsonic and Supersonic flows – shock theories – 2-D planar shocks and property changes across the shocks 12 AE 651- Prof Bhaskar Roy, IIT B Lect-1

Pre-requisites Some prior knowledge of all the above subjects is a pre-requisite for this course 13 AE 651- Prof Bhaskar Roy, IIT B Lect-1

Working of Compressors and Turbines Lift • Compressors perform Drag work on the passing air. Work is done on the air often with the help of airfoil shapes • Turbine extract work from the passing air Highly Cambered often with the help of Blade section for airfoil shapes Turbines 14 AE 651- Prof Bhaskar Roy, IITB Lect-1

Employing Airfoils Compressor Airfoils Turbine Airfoil T- 6 blade section 15 AE 651- Prof Bhaskar Roy, IIT, B Lect-1

Employing Airfoils a) Normal b) Excessive turning c) Excessive Stagger Diffusing Flow in Axial Compressor Passages 16 Lect-1 AE 651- Prof Bhaskar Roy, IITB

Employing Airfoils Accelerating Flow in a Turbine Passage 17 AE 651- Prof Bhaskar Roy, IITB Lect-1