Applied Thermodynamics - II, Question Paper of Mechanical Engineering 4th Semester, Download Question Paper Applied Thermodynamics 2

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Total No. of Questions : 09]

B. Tech. (Sem. – 4th)

APPLIED THERMODYNAMICS - II

SUBJECT CODE : ME – 208 (2008 Batch)

 Paper ID : [A0811]

Time : 03 Hours

Instruction to Candidates:

1. SECTION-A is COMPULSORY consisting of TEN questions carrying

TWO marks each.

2. SECTION-B contains FIVE questions carrying FIVE marks each and

students has to attempt any FOUR questions.

3. SECTION-C contains THREE questions carrying TEN marks each and

students has to attempt any TWO questions.

SECTION-A

l. Answer briefly :

(a) What is delay period and what are the factors that affect the delay

period ?

(b) What is the need of supercharging in I.C. Engines ?

(c) List the positive displacement type compressors of rotary type.

(d) Define prewhirl. Explain its effect on the impeller of a centrifugal

compressor.

(e) Explain the terms : mean effective pressure & swept volume used in

case of internal combustion engines.

(f) Explain the terms slip factor and power input used in case of centrifugal

compressor.

(g) What are the factors that affect the performance of axial flow

compressor ?

(h) Write the field of applications of axial flow compressors.

(i) Differentiate between closed & semi-closed gas turbines.

(j) State the fundamental difference between the Jet propulsion & Rocket

Propulsion

SECTION-B

2. Bring out clearly the process of combustion in C.I. engines & also

explain the various stages of combustion.

3. Describe the phenomenon of detoriation in C.I. engines. On what factors

does detoriation depend ?

4. Describe the function of impeller and diffuser in a centrifugal compressor.

5. Draw the velocity triangles for hub, mean and tip radius for free vortex

conditions.

6. Discuss briefly the methods employed for improvement of thermal efficiency

of open cycle gas turbine plant.

SECTION-C

7. A gas turbine unit receives at 1 bar and 300 K and compresses it

adiabatically to 6·2 bar with efficiency of the compressor 88%. The fuel

has a heating value of 44180 kJ/kg and the fuel/air ratio is 0·017 kg fuel/

kg air. The turbine internal efficiency is 90%, calculate the compressor

work, turbine work and thermal efficiency.

8. Explain with neat sketch working of an Axial flow compressor. How does

it differ from centrifugal compressor ?

9. A centrifugal compressor with an overall diameter of 1 m runs at 5000

r.p.m. Air is supplied to the centrifugal compressor at 20°C and 100 kPa.

The mass flow rate of air is 25 kg/s. Isentropic pressure ratio is 2·5.

Calculate :

(a) Isentropic efficiency

(b) The rotor power

(c) The shaft power.

Assume slip factor of 0·9