Answer to Question #217711 in Mechanical Engineering for Gopi

Question

An engine 200 mm bore and 300 mm stroke works on Otto cycle. The clearance volume is 0.0016 m3. The initial pressure and temperature are 1 bar and 60°C. If the maximum pressure is limited to 24 bar, find : (i) The air-standard efficiency of the cycle (ii) The mean effective pressure for the cycle. Assume ideal conditions

Answer 1

i.

$η=1-\frac{1}{r^{\gamma-1}} = 1-\frac{1}{8.85^{1.4-1}}=0.5879\\ \implies η= 58.19 \%$

ii.

$pm= \frac{P_1 r[r^{\gamma-1}-1]*[r_p-1]}{(r-1)(\gamma-1)}\\ pm= \frac{8.85[8.85^{1.4-1}-1]*[0.134]}{(0.4)(7.85)}\\ pm=0.526$