A 8-cylinder, 4-stroke petrol engine of 80 mm bore and 90 mm stroke has a compression ratio of 7. It is tested at 4000 rpm on a dynamometer which has 54 cm arm. During a 10 minute test, the dynamometer reads 400 N and the engine consumes 4.75 kg of fuel. Air is supplied at 1 bar and 27°C at the rate of 6.5 kg/min. CV of fuel = 44 MJ/kg. Determine (a) the brake power (b) the brake mean effective pressure (c) the volumetric efficiency (d) the A:F ratio, and (e) the relative efficiency.

Answer rating: 100% (QA)

a The brake power is the power that is available to turn the wheels It is calculated by multiplying the torque by the rotational speed The torque is calculated by multiplying the force by the radius o... View the full answer