# JNTU II B-Tech I Semester Regular Examinations,Thermal Science- November 2008

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JNTU II B.Tech I Semester Regular Examinations, November 2008

Thermal Science

( Common to Mechatronics and Production Engineering)

1. (a) Explain the terms state path, process and cyclic process.

(b) Distinguish between closed system, open system and isolated system with suitable examples.

2. Nitrigen (Cp=1.0 KJ/kg 0k, ?=1.4) Expands through a nozzle at a steady flow rate

of 1000kg/hour from 6 bar to 3.5 bar. Velocity and temperature at inlet to the

nozzle are 100 m/sec and 90 0C respectively. Find the exit area of the nozzle.

3. (a) Prove that violation of the clausius statement leads to violation of the Kelvin

Planck statement of the second law of thermodynamics.

(b) How is entropy defined?

(c) What is available energy and unavailable energy?

4. A gas engine operating on the ideal otto cycle has compression ratio of 6 : 1.

The pressure and temperature at the commencement of compression are 1 bar and

27 0C. The heat added during the constent volume combustion process is 1170 KJ/Kg. Determine the peak pressure and temperature, work output per kg of air and air-standard efficiency. Assume Cv = 0.717 KJ/Kg K and ? = 1.4 for air.

5. (a) Draw the line diagram of the Bell-Coleman refrigeration cycel. Explain with

the help of a P-V diagram, different processes in the cycle.

6. (a) What do you understand by ignition? How it is related with combustion?

(b) Discuss basic requirements of an ignition system.

7. (a) Explain different stages of combustion in S.I.Engine along with p-? diagram.

(b) What is diesel knock? How to minimize knocking in C.I. Engine.

8. (a) Describe the working of semi closed type gas turbine unit with suitable figures.

(b) What are the advantages and limitations of closed cycle gas turbine unit.