Annamalai University 2010-4th Sem B.E Mechanical Engineering , (ESTER) MEEC - 402HEAT ENGINERRING-I ( New regulations ) - Question Paper

B.E. DEGREE EXAMINATION, 2010

(MECHANICAL ENGINEERING)

(FOURTH SEMESTER)

MEEC - 402. HEAT ENGINERRING-I
( New regulations )
[may] [Time-3 hours]

Maximum marks : 60 marks
ans ALL ques..
ans any 1 full ques. from every unit
All ques. carry equal marks.
UNIT-I
1. A singles-stage ,single acting air compresor delivers 06kg of air per minute at 6bar.
The temperature and pressure at the end of suction stroke are 30degree centigrate
and one bar . The bore and stroke of the compressor are 100mm and 150mm respectively
The clearance is 3% of the swept quantity . Assuming the index of compression
and expansion to be 1.3 obtain
i) volumetric efficiency of the compressor
ii)Power needed if the mechanical efficiency is 85%
iii) Speed of the compressor(r.p.m)
[marks 12]
2.Explain with neat sketch the working principle of single stage air compressor.
[marks 12]

UNIT-II
3.A single cylinder double acting steam engine receives steam at 1MPa and
exhausts at 55KPa. The dryness of inlet steam is 96% .The power developed by the
engine when running at 210 .p.m. is 45kW, with steamconsumption of 460kg/hr.
The engine bore is 25 cm and stroke is 37.5cm. The expansionratio is 6,
compute the diagram factor and the indicated thermal efficiency of the engine.
[marks 12]
4. discuss with a neat sketch the working of compond steam engines.
[marks 12]
UNIT-III
5.Explain with a neat sketch of 4 stroke petrol engine . [marks 12]
6.An oil engine with 20 cm cylinder diameter and 30cm stroke works on
theoretical diesel cycle . The intial pressure and temperature of the air
used are one bar and 30 degree centigrate . The cut-off is 10% of the stroke.
obtain the following:
a) Pressure anad temperature at all salient points.
b) Theoretical air standard efficiency
c)Mean effective pressure
d) The power developed by the engine if the
working cycles per minute are 400

presume the compression ratio is 16 an dworking fluid is air .
take all ideal conditions.
[marks 12]
UNIT-IV
7.Explain the subsequent .
a) phenomenon of knocking in SI engines.
b)Effects of knocking
c) Factors affecting knocking
[marks 12]
8.Explain the subsequent
a) Pre flame combustion
b) uncontrolled combustion
c) Controlled combustion
d) After burning
[marks 12]
UNIT-V
9.A test on single cylinder , four stroke oil engine having bore 180 mm
and stroke 360 mm gave the subsequent outcomes . Speed 290 r.p.m.
brake torque 392 Nm.
Indicated mean effective pressure 7.2 bar ,
oil consumption = 3.5kg/hour, cooling water flow 270kg/hr,
cooling water temprature rise 36 degree C, air fuel ratio by weight 25,
exhaust temperature 415 degree C, Barometric pressure 1.013 bar
room tempurature 21 degree C. The fuel has a colorific value of 45,
200KJ/kg and sontains 15% of hydrogen by weight .Draw a heat balance
sheet in terms of KJ/min.
[marks 12]
10. A Single cylinder 4-stroke oil engine works on a diesel cycle .
the subsequent readings were taken when the engine was running at full
Area of indicator card = 3cm(square),Length of the diagram=4cm,
spring constant=10bar/cm, Speed of the ngine =400r.p.m.,
Load on the brake =380N, spring balnce reading=50N diameter of the
brake drum=120cm,fuel consumption 2.8kg/hr,
calorific value of fuel=42,000KJ/kg.
Diameter of the cylinder of the cylinder =16cm,
stoke of the piston=20 cm. obtain
a) mechanical efficiency
b) brake thermal efficiency
c) Brake mean effective pressure.
[marks 12]

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Earning:   Approval pending.