Applied Thermodynamics - II, Question Paper of Mechanical Engineering 4th Semester, Download Question Paper Applied Thermodynamics 15

Roll No. ......................

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.

2) Attempt any Four questions from Section - B.

3) Attempt any Two questions from Section - C.

Section – A

QI)

a) What do you understand by air injection and solid injection system?

b) What is the purpose of engine testing?

c) Discuss the term squish, swirl.

d) What are the various factors that influence the flame speed?

e) Differentiate between a flywheel and governor.

0 Define the term pressure coefficient, prewhirl.

g) What do you mean by surging and choking?

h) Define effectiveness of regenerator.

i) Define the term take off thrust and propulsive power of jet propulsion

system.

j) What are the various assumptions made in practical cycle analysis in

gas turbines?

Section-B

Q2) Find the air fuel ratio of four stroke, single-cylinder, air cooled engine with

fuel consumption. Time for l0cc as 20.4sand air consumption time for 0.1m3

as 16.3s. the load is 17kg at the speed of 3000rpm. Find also brake specific

fuel consumption in g/k wh and brake thermal efficiency. Assume the density

of air as I .1 .175 g/m³ and specific gravity of fuel to be 0.7. The lower heating

value of fuel is 43MJ/kg and dynamometer constant is 5000.

3) Free air of 30 m3/min is compressed from 101.3kPa to 2.23 bar in roots

blower. Determine the power required and isentropic efficiency.

4) The effective jet exit velocity from jet engine is 2700m/s- The forward flight

velocity is 1350m/s and the air flow rate is 78.6kgis. Calculate a) thrust

b) thrust power c) propulsive efficiency'

5) What is rocket propulsion? Compare the working of liquid and solid propellant

rockets.

Q6) Why non-dimensional parameters are used to predict the performance

characteristics of compressor? Derive these parameters from the concept

of dimensional analysis.

Section - C

7) A centrifugal compressor has to deliver 6kg/s of air with pressure ratio of

4: I at 175OO rpm. Initial conditions are static air at 1 bar and 15˚C. Assuming

an adiabatic efficiency of 78%, ratio of whirl speed to tip speed 0.94 and

neglecting all other losses, calculate the tip speed, diameter and rise in total

pressure. Also, determine the external diameter of eye for which the internal

diameter is 12cm and the axial velocity at inlet is 150m/sec. Assume

c_p=1 .005kJ/kgK and  =1.4