A sharp edged circular orifice of diameter 3.8 cm and coefficient of discharge as 0.6 is used to measure air consumption of a four stroke petrol engine. Pressure drop through the orifice is 145mm of water and barometer reads 75.5 cm of Hg. The compression ratio of the engine is 6 and the piston displacement volume is 2000 cm3. The temperature of air is taken to be 26°C. At 2600 rpm, the engine brake power recorded is 29.5kW. The fuel consumption is 0.14 kg/min and the calorific value of fuel used is 43960 kJ/kg. Calculate the following :
(i) Volumetric efficiency.
(ii) Air-fuel ratio.
(iii) Brake means effective pressure.
(iv) Brake thermal efficiency.
(v) Relative efficiency.