Questions from Thermal Fluid Science

Q: Citrus fruits are very susceptible to cold weather, and extended exposure

Citrus fruits are very susceptible to cold weather, and extended exposure to subfreezing temperatures can destroy them. Consider an 8-cm-diameter orange that is initially at 15°C. A cold front moves i...

Q: A 0.083-in-diameter electrical wire at 90

A 0.083-in-diameter electrical wire at 90°F is covered by 0.02-in-thick plastic insulation (k = 0.075 Btu/h⋅ft⋅°F). The wire is exposed to a medium at 50°F, with a combined convection and radiation he...

Q: Chickens with an average mass of 1.7 kg (k

Chickens with an average mass of 1.7 kg (k = 0.45 W/m⋅K and α = 0.13 × 10−6 m2/s) initially at a uniform temperature of 15°C are to be chilled in agitated brine at −7°C. The average heat transfer coef...

Q: Repeat Prob. 17–91E, assuming a thermal contact resistance

Repeat Prob. 17–91E, assuming a thermal contact resistance of 0.01 h⋅ft2⋅°F/Btu at the interface of the wire and the insulation. Data from Prob. 17-91: A 0.083-in-diameter electrical wire at 90°F is...

Q: Natural gas, which is mostly methane CH4, is a fuel

Natural gas, which is mostly methane CH4, is a fuel and a major energy source. Can we say the same about hydrogen gas, H2?

Q: Hailstones are formed in high-altitude clouds at 253 K.

Hailstones are formed in high-altitude clouds at 253 K. Consider a hailstone with diameter of 20 mm that is falling through air at 15°C with convection heat transfer coefficient of 163 W/m2⋅K. Assumin...

Q: A 4-mm-diameter spherical ball at 50°C

A 4-mm-diameter spherical ball at 50°C is covered by 1-mm-thick plastic insulation (k = 0.13 W/m⋅K). The ball is exposed to a medium at 15°C, with a combined co...

Q: An ordinary egg can be approximated as a 5.5-

An ordinary egg can be approximated as a 5.5-cm diameter sphere whose properties are roughly k = 0.6 W/m⋅K and α = 0.14 × 10−6 m2/s. The...

Q: Reconsider Prob. 17–93. Using appropriate software, plot

Reconsider Prob. 17–93. Using appropriate software, plot the rate of heat transfer from the ball as a function of the plastic insulation thickness in the range of 0.5 mm to 20 mm. Di...

Q: Reconsider Prob. 18–58. Using appropriate software, investigate

Reconsider Prob. 18–58. Using appropriate software, investigate the effect of the final center temperature of the egg on the time it will take for the center to reach this temperatur...