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Finding Work and Heat Transfer

Air initially at 100 psia, 500 F undergoes an internally reversible process to 45 psia. For each of the following cases, determine for 10 lbm of air the heat transfer and work, each in Btu, and show the processes on P-v and T-s coordinates.

The process is:
a) Isothermal
b) Adiabatic (Hint: look at other assumptions above)
c) Constant volume

Solution Preview

Please see the attached file.

Problem:

Air initially at 100 psia, 500 F undergoes an internally reversible process to 45 psia. For each of the following cases, determine for 10 lbm of air the heat transfer and work, each in Btu, and show the processes on P-v and T-s coordinates.
The process is:

a) Isothermal
b) Adiabatic (Hint: look at other assumptions above)
c) Constant volume

Solution:
a) The thermodynamic cycle is like in diagram of below:

We will convert everything first to SI and finally, we will give the results in British units as well.

Given: p1 = 100 psia = 6.89 bar
T1 = 500F = 513.5 K
P2 = 45 psia = 3.1 bar
M = 10 lbm = ...

Solution Summary

The solution determines the type of process that a pocket of air has undergone. A heat transfer process being isothermal, adiabatic and constant volumes are determined.

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