Questions from Thermal Fluid Science

Q: Reconsider Prob. 17–114E. Using appropriate software, investigate

Reconsider Prob. 17–114E. Using appropriate software, investigate the effects of the thermal conductivity of the spoon material and the length of its extension in the air on the temp...

Q: A DC motor delivers mechanical power to a rotating stainless steel shaft

A DC motor delivers mechanical power to a rotating stainless steel shaft (k = 15.1 W/mâ‹…K) with a length of 25 cm and a diameter of 25 mm. In a surrounding with ambient air temperatur...

Q: A plane wall with surface temperature of 350°C is attached

A plane wall with surface temperature of 350°C is attached with straight rectangular fins (k = 235 W/mâ‹…K). The fins are exposed to an ambient air condition of 25Â&de...

Q: Pipes with inner and outer diameters of 50 mm and 60 mm

Pipes with inner and outer diameters of 50 mm and 60 mm, respectively, are used for transporting superheated vapor in a manufacturing plant. The pipes with thermal conductivity of 16 W/mâ‹&...

Q: Steam in a heating system flows through tubes whose outer diameter is

Steam in a heating system flows through tubes whose outer diameter is 5 cm and whose walls are maintained at a temperature of 130°C. Circular aluminum alloy 2024-T6 fins (k = 186 W/mâ...

Q: A 75-hp (shaft output) motor that has an

A 75-hp (shaft output) motor that has an efficiency of 91.0 percent is worn out and is replaced by a high-efficiency 75-hp motor that has an efficiency of 95.4 percent. Determine the reduction in the...

Q: Consider steady one-dimensional heat transfer through a multilayer medium.

Consider steady one-dimensional heat transfer through a multilayer medium. If the rate of heat transfer Q is known, explain how you would determine the temperature drop across each layer.

Q: A 0.4-cm-thick, 12-cm

A 0.4-cm-thick, 12-cm-high, and 18-cm-long circuit board houses 80 closely spaced logic chips on one side, each dissipating 0.04 W. The board is impregnated with copper fillings and has an effective t...

Q: A hot surface at 100°C is to be cooled by

A hot surface at 100°C is to be cooled by attaching 3-cm-long, 0.25-cm-diameter aluminum pin fins (k = 237 W/m⋅K) to it, with a center-to-center distance of 0.6 cm. The te...

Q: Reconsider Prob. 17–121. Using appropriate software, investigate

Reconsider Prob. 17–121. Using appropriate software, investigate the effect of the center-to center distance of the fins on the rate of heat transfer from the surface and the overall...