Problems:
4.30
4.40
4.46
4.63
Be sure to read section 4.3.2 in the textbook.
Check the Exam #2 web page on Friday for "things you should know by now."

Answers:
4.30: T₂ = 46.4^oC
4.40: d₂ = 0.2843 m, W-dot = 11,374 kW = 38.8 x 10⁶ Btu/h
4.46: Q-dot = - 6.42 kW (from solution manual)
4.63: m₂ = 6264 kg/h

Hints:
4.30: Consider only the diffuser -- you can ignore the compressor.

4.40: Area * Velocity = Volumetric Flow Rate.

Although the change in kinetic energy is negligible (in terms of the 1st law equation), the velocity may be needed to find another part of the problem. 4.46: This is one case where the compressor is not operating adiabatically...

4.63: A de-superheater is just a box -- there is no work associated with the control volume. MAKE GOOD ASSUMPTIONS.

In general:

• Read EACH word.
• Draw some pictures (one for each state).
• Write the given information.
• Write what it is you are to find.
• Write your assumptions
• Write write the equations you are to use (or might want to use).
• If necessary, find the phase at each state. (you may need this to find the "u"s, "v"s or "h"s)
• Solve the problem...
• PLEASE try to be organized.

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