Special Case of Heat Transfer- Finned Surface.

Ta		(air temperature, deg F)
Ts		(surface temperature, deg F)
do		(fins diameter outside, in)
L		(fins length, ft)
N		(Number of pins per in2)
k		(thermal conductivity, BTU per hr ft per deg F)
h		(heat-transfer coefficient, BTU per hr per ft2 per deg F)