An 8-cylinder, four-stroke engine of 9 cm bore and 8cm stroke with a compression ratio of 7 is tested at 4500 rpm on a dynamometer which has 54 cm arm. During a 10 minutes test the dynamometer scale beam reading was 42 kg and the engine consumed 4.4 kg of the gasoline having a calorific value of 44000kJ/kg. Air 27°C and 1 bar was supplied to the carburetor at the rate of 6 kg/min.

Find (i) the brake power delivered (ii) the brake mean effective pressure (iii) the brake specific fuel consumption (iv) the brake specific air consumption (v) the brake thermal efficiency (vi) the volumetric efficiency and (vii) the air-fuel ratio.

Number of Cylinders,

Bore,

Stroke,

C.R,

N

Brake Arm,

Brake Load,

(i) Brake Power(B.P.) :

(ii) b.m.e.p() :

(iii) b.s.f.c :

(iv) Brake specific air consumption :

(v) Brake thermal efficiency :

(vi) Volumetric efficiency, :

Swept volume for 8 cylinders,

Rate of swept volume,

Theoretical mass flow rate of air at suction conditions,

Volumetric efficiency,

(vii) Air-fuel ratio :