Air entries a compressor in a steady flow at 140KPa, $17^oc$ and 70m/s and leaves at 350 KPa, $127^oc$ & 110m/s. The environment is at 100 KPa, $7^oc$. - (i) The actual amount of work required - (ii) The minimum work required - (iii) The irreversibility of the process -

Mumbai university > MECH > SEM 3 > THERMO

Marks: 10M

Year: Dec 2014

Given:

P1=140 kPa; v1 = 70m/s; T1 = 290K;

P2 = 350kPa; v2=110m/s; T2=400K

P0= 100kPa; T0= 280K;

Solution:

i) Finding work

Q-W = ∆Potential energy + ∆Kinetic energy + ∆Pressure energy

$W = mg(z2-z1) + 1/2m (v2^2 – v1^2) + (H2-H1)$

Assuming m=1kg and Q=0 (adiabatic process)

$-W= 9.8 …