Questions from Thermal Fluid Science

Q: Water enters the tubes of a cold plate at 70°F

Water enters the tubes of a cold plate at 70°F with an average velocity of 40 ft/min and leaves at 105°F. The diameter of the tubes is 0.25 in. Assuming 15 percent of the heat generated is dissipated...

Q: Consider a hollow-core printed circuit board 9 cm high and

Consider a hollow-core printed circuit board 9 cm high and 18 cm long, dissipating a total of 15 W. The width of the air gap in the middle of the PCB is 0.25 cm. If the cooling air enters the 12 cm-wi...

Q: A computer cooled by a fan contains eight PCBs, each dissipating

A computer cooled by a fan contains eight PCBs, each dissipating 10 W power. The height of the PCBs is 12 cm and the length is 18 cm. The cooling air is supplied by a 25-W fan mounted at the inlet. If...

Q: A desktop computer is to be cooled by a fan. The

A desktop computer is to be cooled by a fan. The electronic components of the computer consume 60 W of power under full-load conditions. The computer is to operate in environments at temperatures up t...

Q: Repeat Prob. 2–58 for a gage pressure of 40

Repeat Prob. 2–58 for a gage pressure of 40 kPa. Data from Prob 2-58: The gage pressure of the air in the tank shown in Fig. P2–58 is measured to be 80 kPa. Determ...

Q: Air enters the 1-m2 inlet of an aircraft engine at

Air enters the 1-m2 inlet of an aircraft engine at 100 kPa and 20°C with a velocity of 180 m/s. Determine the volume flow rate, in m3/s, at the engine’s inlet and the mass flow rate, in kg/s, at the e...

Q: Repeat Prob. 6–89 for a computer that consumes 100

Repeat Prob. 6–89 for a computer that consumes 100 W of power. Data from Prob. 6-89: A desktop computer is to be cooled by a fan. The electronic components of the computer consume 60 W of power under...

Q: A 4-m × 5-m × 6-m

A 4-m × 5-m × 6-m room is to be heated by an electric resistance heater placed in a short duct in the room. Initially, the room is at 15°C, and the local atmospheric pressure is 98 kPa. The room is lo...

Q: A house has an electric heating system that consists of a 300

A house has an electric heating system that consists of a 300-W fan and an electric resistance heating element placed in a duct. Air flows steadily through the duct at a rate of 0.6 kg/s and experienc...

Q: A long roll of 2-m-wide and 0.

A long roll of 2-m-wide and 0.5-cm-thick 1-Mn manganese steel plate (ρ = 7854 kg/m3 and cp = 0.434 kJ/kg·°C) coming off a furnace at 820°C is to be que...