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Q1. A six cylinder 4 stroke diesel engines has a bore of 230 mm and stroke of 600 mm.

The brake mean effective pressure is 8 bar at 900 rev/min and the brake specific fuel consumption is 0.139 kg/kWh when burning a fuel with a calorific value of 46 MJ/kg.

The air to fuel ratio by mass is 28:1 at atmospheric conditions of 0.95 bar and 17ºC.

(a) Show that the brake mean effective pressure is directly proportional to engine torque and independent of speed.

(b) Calculate EACH of the following:

(i) The shaft torque

(ii) The brake thermal efficiency

(iii) The volumetric efficiency of the engine.

Note: For air R = 0.287 kJ/kgK