Anna University Coimbatore 2011 B.E Aeronautical Engineering Annauniversity coimbatore, / B.TECH:IL/, , 080180015-PROPULSION I - Question Paper

ANNA UNIVERSITY OF TECHNOLOGY, COIMBATORE

B.E./B.TECH. DEGREE EXAMINATIONS: APRIL/MAY 2010

REGULATIONS: 2008

THIRD SEMESTER: AERONAUTICAL ENGINEERING

080180015-PROPULSION I

TIME: 3 HOURS MAX.MARKS:100

PART-A

(20*2=40MARKS)

ANSWER ALL QUESTIONS

 

1.       List any two advantages of a turboprop engine.

2.       When does the diffuser in an inlet stall?

3.       Compare turbojet and turbo-prop engines.

4.       What are the methods of thrust augmentation?

5.       Give general thrust equation.

6.       Distinguish inlet flow operation for level cruise and take off operations.

7.       What are the factors to be considered while designing a subsonic inlet?

8.       What are the factors affecting the combustion chamber design?

9.       What is meant by sub critical mode of inlet operation? State its advantages and disadvantages.

10.   State the advantages and disadvantages of annular combustor

11.   List the functions of a nozzle with regards of gas turbine engine.

12.   Define combustion intensity?

13.   What is choked nozzle?

14.   Write down the difference between centrifugal and axial flow compressors.

15.   Distinguish between surging and stalling.

16.   Define slip factor.

17.   De4fine degree of reaction for an axial flow compressor.

18.   What are the types of thrust reversers?

19.   Draw the exit velocity diagram for a backward curved impellor.

20.   Draw the h-s diagram for a single stage of an axial flow compressor.

PART-B

(5*12=60 MARKS)

ANSWER ANY FIVE QUESTIONS

21. (a )What is thrust augmentation? Explain any two methods of thrust augmentation with neat sketches (7)

(b) Briefly explain with neat sketch operating principles of turbofan engine (5)

22. Compare the characteristics, advantages & disadvantages of turbojet, turbofan and turboprop engine

23. (a)what are the different modes of inlet operation? Explain with suitable sketches (6)

(b) Derive the relation between area ratio Amax/Ai and external deceleration ratio ui/ua (6)

24. (a) Explain the starting problems in supersonic inlets and methods to overcome them (8)

(b) Explain super-critical operation of supersonic inlets. (4)

25. How is gas turbine combustion chambers classified? Mention any three types of combustion chambers with neat sketches. Discuss also the relative merits and demerits.

26. (a) Explain the various factors those affect the combustion chamber performance. (8)

(b) Write short notes on flame tube cooling. (4)

26. (a) Discuss the factors affecting stage pressure rise of an axial flow compressor with suitable sketches (6)

27. (b) Explain the working of a centrifugal compressor and draw the velocity triangles. (6)

28. Write short notes on (4+4+4)

(a) Ejector & Variable area nozzles.

(b) Thrust reversing

(c) Over-expanded and Under-expanded Nozzles with neat sketches

*****THE END*****