Simulation of Heat Transfer in Tubes in Fluent Software
 

hi,
a steel tube is used to transfer cold materials. The internal diameter of the pipe is 36 mm and the thickness
It is 2 mm. Medium temperature and ambient air are 6 degrees Celsius and 23 degrees Celsius, and coefficients
The corresponding displacement is 400 W / m2k and 6 W / m2k respectively.
A) What is the rate of heat transfer to the drug per unit length of the tube?
B) If the insulation of calcium silicate is of thickness of 04 mm and with conductivity coefficient of 0.5 W / mk on the pipe What is the rate of heat transfer per unit pipe?

An overall heat transfer coefficient (defined for the outer/larger area) for a circular pipe with internal and external convective heat transfer can be written in the following way.

I wouldn't say it's right to define a heat transfer rate per unit length as it depends on the flow rate (perhaps a heat transfer *coefficient* per unit length)