Solution of Numerical asked in GTU question of 04.08.2021

Q.5 (C) OR

A four cylinder, four stroke petrol engine 75 mm bore by 90 mm stroke operates on Otto cycle and has a compression ratio of 6:1.the efficiency ratio based on indicated work being 55%, calculate indicated thermal efficiency. Take specific heat ratio 1.4, when running at 40 rps, the engine develops a brake mean effective pressure of 725 kN/m2, 9.2 kg of fuel/hr. of calorific value of 44000 kj/kg. calculate brake thermal efficiency, the mechanical efficiency and specific fuel consumption in kg/kwh