Questions from Thermal Fluid Science

Q: Reconsider Prob. 8–20. Using appropriate software, study

Reconsider Prob. 8–20. Using appropriate software, study the effects of the varying heat added to the working fluid and the source temperature on the entropy change of the working fluid, the entropy c...

Q: During the isothermal heat rejection process of a Carnot cycle, the

During the isothermal heat rejection process of a Carnot cycle, the working fluid experiences an entropy change of –0.7 Btu/R. If the temperature of the heat sink is 95°F,...

Q: It is well known that cold air feels much colder in windy

It is well known that cold air feels much colder in windy weather than what the thermometer reading indicates because of the “chilling effect” of the wind. This effect is due to the increase in the co...

Q: Air is compressed by a 40-kW compressor from P1 to

Air is compressed by a 40-kW compressor from P1 to P2. The air temperature is maintained constant at 25°C during this process as a result of heat transfer to the surrounding medium at 20°C. Determine...

Q: Refrigerant-134a enters the coils of the evaporator of a refrigeration

Refrigerant-134a enters the coils of the evaporator of a refrigeration system as a saturated liquid vapor mixture at a pressure of 140 kPa. The refrigerant absorbs 180 kJ of heat from the cooled space...

Q: A rigid tank contains an ideal gas at 40°C that

A rigid tank contains an ideal gas at 40°C that is being stirred by a paddle wheel. The paddle wheel does 200 kJ of work on the ideal gas. It is observed that the temperature of the ideal g...

Q: A rigid vessel is filled with a fluid from a source whose

A rigid vessel is filled with a fluid from a source whose properties remain constant. How does the entropy of the surroundings change if the vessel is filled such that the specific entropy of the vess...

Q: A rigid vessel filled with a fluid is allowed to leak some

A rigid vessel filled with a fluid is allowed to leak some fluid out through an opening. During this process, the specific entropy of the remaining fluid remains constant. How does the entropy of the...

Q: Is a process that is internally reversible and adiabatic necessarily isentropic?

Is a process that is internally reversible and adiabatic necessarily isentropic? Explain.

Q: One lbm of R-134a is expanded isentropically in a closed

One lbm of R-134a is expanded isentropically in a closed system from 100 psia and 100°F to 10 psia. Determine the total heat transfer and work production for this process.