D B3D004 Pages: 2

Reg. No. Name:
APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
THIRD SEMESTER B.TECH DEGREE EXAMINATION, JULY 2017

Course Code: AU 201
Course Name: S. I. ENGINES AND COMBUSTION (AU)
Max. Marks: 100 Duration: 3 Hours
PARTA

Answer any 3 questions.

1. In an ideal Otto cycle, the compression ratio is 8. The initial pressure and temperature
of the air are | bar and 100°C, The maximum pressure in the cycle is 50 bar. For 1 kg
of air flow, calculate the values of the pressure, volume and temperature at the four
salient points of the cycle. What is the ratio of heat supplied to heat rejected? (10)

2. Discuss in detail the different losses accounted in actual cycle analysis. (10)

3. Discuss the effect of various engine variables on the phenomenon of detonation. (10)

4. (a) Define the following terms- Octane number, LCV, HCV, HUCR. (4)
(b) In a bomb calorimeter test of gasoline, the calorific value measured was found to

be 46.9 MJ/kg. If the fuel contains 14.4 % 11) by mass, calculate the LCV of the
gasoline sample tested.

Given: the enthalpy of vaporisation of water at 25°C as 2.3 MJ/kg. (6)

PART B
Answer any 3 questions.

5. Carry out the exact analysis to calculate the air-fuel ratio for a simple carburettor.

(10)
6. Explain briefly the different systems in MPFI system with neat sketch. (10)
7. Explain the different components of a basic ignition system considering the battery
ignition system with neat sketches. (10)
8. Explain briefly the theoretical scavenging processes with neat figures. (10)
PART C

Answer any 4 questions.
9. Explain the different drives used for operating the valve mechanism with neat figures.
(10)

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