1st SESSIONAL EXAMINATION 2012-13
BRANCH – ME
SEMESTER- V
Course: B.Tech. Year: 3rd
Sub: IC Engines & Compressors Subject Code: EME- 505
Maximum Marks: 30 Time: 1.30 hrs
Section A:
2x6 = 12
Q.1) Answer the following question in
brief
(a) Explain
the difference between inlet valve and inlet port.
(b) What
is cracking?
(c) Define
volumetric efficiency of an IC engine with diagram.
(d) What
are the assumptions of a air standard cycle?
(e) Explain
the concept of indicator thermal efficiency.
(f) What
are the general refinery processes?
Section B:
Q.2) Answer
any three of the following questions 6 x 3 = 18
(a) Compare between four stroke and two stroke IC engines.
(b) What is
compression ratio? What is its range for (i) the SI engine (ii) CI engine? What
factors limit the compression ratio in each type of engine?
(c) An ideal Otto cycle has compression ratio of 8 and
initial conditions are 1 bar and 15°C. Heat added during constant volume
process is 1045 kJ/kg. Find:
(i)
Maximum cycle temperature
(ii)
Air standard efficiency
(iii)
Work done per kg of air
(iv)
Heat rejected
Take: Cv = 0.7175 kJ/kg-K and γ = 1.4
(d) A diesel engine
develops 5 kW. It’s indicated thermal efficiency is 30% and mechanical
efficiency 57%. Estimate the fuel consumption in (i) kg/hr, (ii) litres/hr,
(iii) Indicated specific fuel consumption, and (iv) brake
specific fuel consumption.
L.C.V. of diesel oil = 42000 kJ/kg.
(e) Compare the actual cycle and its deviation from
theoretical cycles in IC engines.