# Reversible work of compression

1. Jun 21, 2017

1. The problem statement, all variables and given/known data
Air enters a compressor at 100 [Kpa] and 10 [c], the air leave the compressor at 12[Mpa]
the isentropic efficiency η is 87%, calculate:
• work done
• reversible work
• irreversibility

2. Relevant equations

T2=T1(P2/P1)(1.4-1)/1.4
W = (Cp(T2-T1))/η
Wrev=Δh - T0Δs
Δs = cpln(T2/T1) - Rln(P2/P1)
3. The attempt at a solution

Work done can be calculated with:
T2=T1(P2/P1)(1.4-1)/1.4
W = (Cp(T2-T1))/η
T1 , P1 , P2 are given.
Δs = cpln(T2/T1) - Rln(P2/P1)
I tried to find Wrev with Δh - T0Δs
and Δs = cpln(T2/T1) - Rln(P2/P1)

• work : -338.2 kj/kg
• reversibility : -317.4 kj/kg
• irreversibility : 20.8 kj/kg

2. Jun 26, 2017

### PF_Help_Bot

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