In: Mechanical Engineering
A ship is fitted with six-cylinder CI engine of 75 mm bore and 100 mm stroke. The engine has a brake power output of 110 kW at 370 rpm. The volumetric efficiency at this operating condition, referred to ambient conditions, of 1.013 bar and 20˚C is 80%. You have just fitted a mechanically driven supercharger which has isentropic efficiency of 0.7 and the pressure ration of 1.6. The supercharged version of the engine has a volumetric efficiency of 100% referred to supercharged delivery pressure and temperature. It is assumed that the indicated power developed, per unit volume flow rate of induced air at ambient, is the same for normal and supercharged engine. Determine the net increase in brake power to be expected from the supercharged engine. Take the mechanical efficiency of the engine to be 80% in both cases and mechanical efficiency of the drive from the engine to supercharger as 95%.