Problem#2 (Marks

=40

) [Answer in the space provided, show important calculation steps]\ Air enters a compressor operating at steady state with a pressure of

100kPa

and temperature of

20\\\\deg C

. The volumetric flow rate at the inlet is

0.50(m^(3))/(s)

, and the flow area at inlet is

0.025m^(2)

. At the exit, the pressure is

250kPa

, the temperature is

140\\\\deg C

, and the velocity is

20(m)/(s)

. Heat transfer from the compressor to its surrounding occurs at a rate of

1.4kW

. Potential energy effects are negligible. The air behaves as an ideal gas as it flows through the compressor. For air. gas constant

R=0.287

k(J)/(kg.K)

, specific heat

C_(p)=1.01k(J)/(kg.K)

, and specific heat ratio

\\\\gamma =1.4.,[0\\\\deg C

]

=

[

273(K)]

\ Determine: (a) the velocity of air at inlet, in

(m)/(s)

, (b) the mass flow rate of air, in

k(g)/(s)

, (c) the compressor power input, in

kW

, (d) the isentropic efficiency of compressor

(\\\\eta _(c))

, and

(e)

the change of specific entropy from inlet to exit, in

k(J)/(kg.K)

.

Problem\#2 (Marks =40 ) [Answer in the space provided, show important calculation steps] Air enters a compressor operating at steady state with a pressure of 100kPa and temperature of 20C. The volumetric flow rate at the inlet is 0.50m3/s, and the flow area at inlet is 0.025m2. At the exit, the pressure is 250kPa, the temperature is 140C, and the velocity is 20m/s. Heat transfer from the compressor to its surrounding occurs at a rate of 1.4kW. Potential energy effects are negligible. The air behaves as an ideal gas as it flows through the compressor. For air; gas constant R=0.287 kJ/(kgK), specific heat Cp=1.01kJ/(kgK), and specific heat ratio =1.4.[0C=273K] Determine: (a) the velocity of air at inlet, in m/s, (b) the mass flow rate of air, in kg/s, (c) the compressor power input, in kW, (d) the isentropic efficiency of compressor (c), and (e) the change of specific entropy from inlet to exit, in kJ/(kg.K)