The diagram below shows a “hot air blower” consisting of a fan, an electrical heating element and a nozzle. The flow of
Posted: Fri Apr 29, 2022 10:54 am
The diagram below shows a “hot air blower” consisting of a fan, an electrical heating element and a nozzle. The flow of air through the blower is horizontal.
The power input to drive the fan is 250 J/s and the power input to the heating element is 1000 J/s. During its passage through the blower, the air experiences a heat loss of 20 J/s. A steady flow of air enters the fan at a pressure of 1 bar, a temperature of 20 oC, a velocity of 10m/s, and a mass flow rate of 0.05 kg/s. For air, take R = 287 J/kgoK and cp = 1005 J/kgoK. If the specific enthalpy of the air is increased by 24.1 kJ/kg in its passage through the system, determine the following:
i) The velocity of the air at the exit.
ii) The temperature and density of the air at exit
The power input to drive the fan is 250 J/s and the power input to the heating element is 1000 J/s. During its passage through the blower, the air experiences a heat loss of 20 J/s. A steady flow of air enters the fan at a pressure of 1 bar, a temperature of 20 oC, a velocity of 10m/s, and a mass flow rate of 0.05 kg/s. For air, take R = 287 J/kgoK and cp = 1005 J/kgoK. If the specific enthalpy of the air is increased by 24.1 kJ/kg in its passage through the system, determine the following:
i) The velocity of the air at the exit.
ii) The temperature and density of the air at exit