The average surface temperature of the head of a person when it is not covered and is subjected to
winds is to be determined.
Assumptions 1 Steady operating conditions exist. 2 Radiation effects are negligible. 3 Air is an ideal gas
with constant properties. 4 One-quarter of the heat the person generates is lost from the head. 5 The head
can be approximated as a 30-cm-diameter sphere. 6 The local atmospheric pressure is 1 atm.
Properties The properties of air at 1 atm pressure and the free stream temperature of 10°C are (Table A-15)