A compression-ignition engine with compression ratio of 14 is being designed. Pressureand temperature at the bottom dead centre are 1.3 bar and 400K. The engine operatesaccording to the standard Diesel cycle. Assume polytrophic index to be 1.33. Computepressure and temperature at the top dead centre

An Sl engine with a compression ratio rc = 10.1:1 operates on the air standard Otto cycle at 4500 RPM. Maximum temperature in the cycle is 2700 °K and maximum pressure is 8200 kPa. The pressure in the cylinder when the exhaust valve opens is 600 KPa and the exhaust pressure is 98 kPa. The exhaust valve effectively opens at 56° ÞBDC. Calculate: 1. Time of exhaust blowdown in sec 2. The average temperature of the exhaust during the exhaust stroke in °K 3. The maximum flow velocity through the exhaust valve at the start of the blowdown process assuming chocked flow conditions in (m/sec)

14 A six-cylinder SI engine with a compression ra tio of 10.5:1 oper ates on a four-stroke cycle at 3000 RPM. Air enters the cylinders at T = 110 F and P = 12.8 psia. The intake valve closes at 20° BDC and combustion starts when the spark plug fires at 15 6TDC. Con- necting rod length is 6.64 in. and crank offset is 1.66 in. Calculate: (a) Cylinder temperature at start of combustion using air-standard Otto cyde analysis ['F] (b) Cylinder temper ature when spark plug fires assuming compression doesn't start until intake valve closes. ['F]