1st SESSIONAL EXAMINATION 2012-13
BRANCH – ME
Course: B.Tech. Year: 3rd
Sub: IC Engines & Compressors Subject Code: EME- 505
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?
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.