Register Number
SATHYABAMA UNIVERSITY
(Established under section 3 of UGC Act, 1956)
Course & Branch: B.E-P-MECH
Title of the Paper: Applied Thermal Engineering Max. Marks: 80
Sub. Code: 615PT202 (2008/09/2010-JAN)
Time: 3 Hours
Date: 09/12/2010
Session: FN
______________________________________________________________________________________________________________________
1.
PART - A
(10 X 2 = 20)
Answer ALL the Questions
Enumerate the various parts of an IC engine.
2.
What are the properties of lubricating oil?
3.
Differentiate between supercharging and turbocharging.
4.
List various methods available for finding the friction of an
engine.
5.
What is meant by volumetric efficiency of a compressor?
6.
Why are nozzles made convergent and divergent?
7.
List out the important industrial and commercial applications of
refrigeration.
8.
Differentiate between vapour compression refrigeration over
vapour absorption system.
9.
How is the psychrometric chart prepared?
10. Define air conditioning.
PART – B
(5 x 12 = 60)
Answer All the Questions
11. (a) Explain the working principle of four stroke diesel engine
with suitable sketch.
(b) What are the requirements of an ignition system?
(or)
12. (a) Write short notes on knocking.
(b) Explain the working principle of splash type lubrication
system with neat sketch.
13. Explain any one microprocessor based fuel injection system for
IC engine and their advantages.
(or)
14. The following data is given for a single cylinder four stroke oil
engine.
Cylinder diameter = 18cm
Stroke = 36cm
Speed of engine = 286 rpm
Brake power = 375Nm
Mean effective pressure = 7bar
Fuel consumption = 3.881/hr
Specific gravity of fuel = 0.8
C.V of fuel = 44500kJ/kg
Air fuel ratio = 25:1
Ambient air temperature = 21C
Cp of gases 1.2kJ/kgC
Exhaust gas temperature = 415C
Cooling water circulated = 4.2kg/min
Rise in temperature of cooling water = 28C
Find mechanical, indicated thermal efficiency and draw heat
balance sheet on percentage basis.
15. A single stage double acting air compressor delivers air at 7 bar.
The pressure and temperature at the end of suction stroke are 1
bar and 27C. It delivers 2m3 of free air per minute when the
compressor is running at 300rpm. The clearance volume is 50%
of the stroke volume. The pressure and temperature of ambient
air are 1.03bar and 20C.
Index of compression = 1.3, Index of re expansion = 1.35
Find (a) the volumetric efficiency of the compressor (b) IP of
the compressor and B.P. if the mechanical efficiency is 80%.
(or)
16. Derive the expressions for the velocity and flow through the
nozzle in terms of initial pressure, specific volume, area of cross
section, final pressure and index n of frictionless adiabatic
expansion.
17. Draw a neat sketch of air refrigeration system working of Bell –
Coleman cycle and explain its working.
(or)
18. Explain the working principle of vapour absorption refrigeration
system with suitable sketch and draw the H – S diagram.
19. A sling psychrometer reads 44C DBT and 30C WBT. Calculate
the following (a) specific humidity (b) relative humidity (c) dew
point temperature.
(or)
20. Draw a neat diagram of air conditioning system required in
winter season. Explain the working of different components in
the circuit.