Consider a person who is trying to keep cool on a hot summer day by turning a fan on and exposing his entire body to air flow The air temperature is 85 deg F and the fan is blowing air at a velocity of 6 ft s If the person is doing light work and generating sensible heat at a rate of 300 Btu h, det...

A fan is blowing air over the entire body of a person The average temperature of the outer surface o ...

Consider a person who is trying to keep cool on a hot summer day by turning a

Question:

Consider a person who is trying to keep cool on a hot summer day by turning a fan on and exposing his entire body to air flow. The air temperature is 85°F and the fan is blowing air at a velocity of 6 ft/s. If the person is doing light work and generating sensible heat at a rate of 300 Btu/h, determine the average temperature of the outer surface (skin or clothing) of the person. The average human body can be treated as a 1-ft-diameter cylinder with an exposed surface area of 18 ft². Disregard any heat transfer by radiation. What would your answer be if the air velocity were doubled? Evaluate the air properties at 100°F.

85°F 6 ft/s 300 Btu/h 11