Answer:
a. Wa = 73.14 Btu/lbm
b. Sgen = 0.05042 Btu/lbm °R
c. Isentropic efficiency is 70.76%
d. Minimum specific work for compressor W = -146.2698 Btu/lbm [It is negative because work is being done on the compressor]
Explanation:
Complete question is as follows;
Air initially at 120 psia and 500oF is expanded by an adiabatic turbine to 15 psia and 200oF. Assuming air can be treated as an ideal gas and has variable specific heat.
a) Determine the specific work output of the actual turbine (Btu/lbm).
b) Determine the amount of specific entropy generation during the irreversible process (Btu/lbm R).
c) Determine the isentropic efficiency of this turbine (%).
d) Suppose the turbine now operates as an ideal compressor (reversible and adiabatic) where the initial pressure is 15 psia, the initial temperature is 200 oF, and the ideal exit state is 120 psia. What is the minimum specific work the compressor will be required to operate (Btu/lbm)?
solution;
Please check attachment for complete solution and step by step explanation
Answer:
Pressure- temperature diagram of the fluid is the phase lines that separate all the phases.
Explanation:
Step1
Pressure temperature diagram is the diagram that represents the all the phases of the fluid by separating a line. There is no phase change region in the pressure temperature diagram out of 15 possible diagrams. There are three lines that separate the phase of the fluid. These three lines are fusion, vaporization and sublimation.
Step2
The intersecting point of these lines is triple point of fluid. Out of 15 possible phase diagram, only pressure temperature diagram has triple point as a point. In other diagrams phase change region is present and triple point is not a point. Critical point is the point in all possible property diagrams.
Pressure temperature diagram is shown below:
Answer:
slenderness ratio = 147.8
buckling load = 13.62 kips
Explanation:
Given data:
outside diameter is 3.50 inc
wall thickness 0.30 inc
length of column is 14 ft
E = 10,000 ksi
moment of inertia 

Area 


r = 1.136 in
slenderness ratio 

buckling load 

