Question

mean effective pressure is 8.5 Pecific fuel consumption is 3009 g/kWh, and the indicated A A six-cylinder, four-stroke gasoline engine having a bore of 90 mm and stroke of 100 mm has a compression ratio 8. On test, it develops a torque of 240 Nm when it was running at 2500 rpm. Given that the ratio of the indicated thermal efficiency to the theoretical air standard (a) The calorific (heat) value of the fuel Qv, (2 marks) (b) The indicated power of the engine, (2 marks) (c) The Corresponding fuel consumption, (2 marks) (d) The mechanical efficiency (2 marks) (e) During the test, (C10H22) is burnt using an air-fuel ratio of 13:1 by weight. Determine the complete volumetric analysis of the products of combustion, if the whole amount of hydrogen burns to form water vapour and there is neither any free oxygen nor any free carbon. The carbon burns to CO2 and CO. (6 marks)

Answer 1

C10H22 & O2 Cor CO2 t I1 H2O Mole of On consumed in combustion of H2 X 0.007042. 2 1387 31 of O2 mole left for Carbon = 0094697-003873) - 0.055966 kmol. Cio + 02 cot CO2 0.055966 x 0.007042 nty 007042 X 11 0.085966 Z N = 0.02149682 x = 0.02992. y = 0.03447

Mole of H20 = 0.0387311 Mole of Na = 3.76X 0094697 033 = 0.356061 mole Mole of co = 0.043 Mole of O2 = 0:03447. Volume t. of H2O = Nozo Mole of H₂O -X1oo- Total mole X 100 En 0.0387311 X100 0.47226 = 8.27. 75. 395% Similarly, N2= co 9.14 Cor= 7.3%.