# أريد حل لهذه الأسئلة في Thermodynamic

#### almjrshi

##### عضو جديد
[FONT=&quot] the exhaust nozzle of a jet engine expands air at 400 Kpa and 190 C adiabatically to 100 Kpa. Determine the air velocity at the exit when the inlet velocity is low and the nozzle isentropic efficiency is 90 percent.[/FONT]

2- consider a steam power plant operating on the ideal Rankine cycle. Steam enters the turbine at 2 MPa and 350 C and is condensed in the condenser at a pressure of 10 Kpa. Determine (a) the thermal efficiency of this power plant, (b) the thermal efficiency if steam is superheated to 700 C instead of 350 C, and (c) the thermal efficiency if the condenser pressure is raised to 50 KPa while the turbine inlet is maintained at 700 C and 2 MPa.

3- Air enters the compressor of a regenerative gas-turbine engine at 300 K and 100 KPa, where it is compressed to 700 KPa and 550 K. The regenerator has an effectiveness of 80 percent, and the air enters the turbine at 1300 K. For a turbine efficiency of 85 percent, determine (a) the amount of heat transfer in the regenerator and (b) the thermal efficiency. Assume Constant specific heat for air. (Cp = 1.005 KJ/Kg.k, Cv = 0.718 KJ/Kg.k, R = 0.287 KJ/Kg.K, and K = 1.4 )

4- A refrigerator uses refrigerant-134a as the working fluid and operates on the ideal vapor-compression refrigeration cycle. The refrigerator enters the evaporator at 100 KPa with a quality of 30 percent. If the compressor consumes 450 W of power, determine (a) the mass flow rate of the refrigerant, (b) the condenser pressure, and (c) the COP of the refrigerator.​

### مواضيع مماثلة

#### احمد_1976

##### عضو جديد
apply the first low of thermodynamic for open systems