Cold air at 10 degree C flows over a 2cmOD tube as illustrat

Cold air at 10 degree C flows over a 2-cm-OD tube, as illustrated in Fig. P1-13. The outside surface of the tube is maintained at 110 degree C. If the heat transfer coefficient between the outside surface of the tube and the air is 100 W/(m^2 middot degree C), determine the rate of heat flow to the air over the 5-m length of the tube.

Solution

Convective heat transfer = hA dT

h= 100 w/m2c

A= pi *D*L = 0.314m2

dT=110-10=100C

Q=100*0.314*100=3140w