Question

A person extends his uncovered arms into the windy air outside at 54°F and 36 mph in order to feel nature closely as shown in the figure. Initially, the skin temperature of the arm is 84°F. Treating the arm as a 2-ft-long and 3-in-diameter cylinder, determine the rate of heat loss from the arm. It is given that the properties of air at 1 atm and the film temperature of 69°F are (Table A-15E) k = 0.01455 Btu/h·ft·°F, ν = 0.1638 × 10⁻³ ft²/s, and Pr = 0.7308.

The rate of heat loss from the arm is  Btu/h

Answer 1