Questions from Thermal Fluid Science


Q: Air at 500 kPa and 400 K enters an adiabatic nozzle at

Air at 500 kPa and 400 K enters an adiabatic nozzle at a velocity of 30 m/s and leaves at 300 kPa and 350 K. Using variable specific heats, determine (a) the isentropic efficiency, (b) the exit veloci...

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Q: Helium gas enters a nozzle whose isentropic efficiency is 94 percent with

Helium gas enters a nozzle whose isentropic efficiency is 94 percent with a low velocity, and it exits at 14 psia, 180°F, and 1000 ft/s. Determine the pressure and temperature at the nozzle inlet.

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Q: An inventor claims to have invented an adiabatic steady flow device with

An inventor claims to have invented an adiabatic steady flow device with a single inlet-outlet that produces 230 kW when expanding 1 kg/s of air from 1200 kPa and 300°C to 100 kPa. Is this claim valid...

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Q: An adiabatic capillary tube is used in some refrigeration systems to drop

An adiabatic capillary tube is used in some refrigeration systems to drop the pressure of the refrigerant from the condenser level to the evaporator level. R-134a enters the capillary tube as a satura...

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Q: Helium gas is throttled steadily from 400 kPa and 60°C

Helium gas is throttled steadily from 400 kPa and 60°C. Heat is lost from the helium in the amount of 1.75 kJ/kg to the surroundings at 25°C and 100 kPa. If the entropy of the helium increases by 0.34...

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Q: A completely reversible air conditioner provides 36,000 Btu/h

A completely reversible air conditioner provides 36,000 Btu/h of cooling for a space maintained at 70°F while rejecting heat to the environmental air at 110°F. Calculate the rate at which the entropie...

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Q: Determine the work input and entropy generation during the compression of steam

Determine the work input and entropy generation during the compression of steam from 100 kPa to 1 MPa in (a) an adiabatic pump and (b) an adiabatic compressor if the inlet state is saturated liquid in...

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Q: Carbon dioxide is compressed in a reversible, isothermal process from 100

Carbon dioxide is compressed in a reversible, isothermal process from 100 kPa and 20°C to 400 kPa using a steady-flow device with one inlet and one outlet. Determine the work required and the heat tra...

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Q: Reconsider Prob. 8–171. Determine the change in the

Reconsider Prob. 8–171. Determine the change in the work and heat transfer when the compression process is isentropic rather than isothermal. Data from Prob. 8-171: Carbon dioxide is compressed in a...

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Q: The compressor of a refrigerator compresses saturated R-134a vapor at

The compressor of a refrigerator compresses saturated R-134a vapor at –10°C to 800 kPa. How much work, in kJ/kg, does this process require when the process is isentropic?

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