. A cylinder with a volumetric displacement of 1477 cm3 is used in a piston aero engine burning iso-octane (C8H18). The density of iso-octane is 720 kg/m3 and air density is 1.225 kg/m3 . Determine (1) the mass of fuel and (2) the mass of air that must fill a cylinder during the injection stroke to achieve combustion with an equivalence ratio of 1.12.

Aheat pump with refrigerant-134a as the working fluid is used to keep a space at 25°c by absorbing heat from geothermal water that enters the evaporator at 500c at a rate of 0.065 kg/s and leaves at 40°c. the refrigerant enters the evaporator at 20°c with a quality of 23 percent and leaves at the inlet pressure as saturated vapor. the refrigerant loses 300 w of heat to the surroundings as it flows through the compressor and the refrigerant leaves the compressor at 1.4 mpa at the same entropy as the inlet. determine: (a) the degrees of subcooling of the refrigerant in the condenser, b)-the mass flow rate of the refrigerant . (c) the heating load and the cop of the pump, and d)-the theoretical minimum power input to the compressor for the same heating load.