Question

What is the unit of heat transfer coefficient?

(a) Watt m^2 / k

(b) Watt m^2 k

(c) Watt / m^2 k

(d) Watt / m^2k^2

I had been asked this question during an interview.

My question is based upon External Mass Transfer in portion Heterogenous Reactions of Bioprocess Engineering

Answer 1

The correct option is (c) Watt / m^2 k

Explanation: Heat flux form a bulk fluid at T∞ to the surface of a spherical particle of diameter dp at TS: Newtons law of cooling:

q = h (T∞ – TS)

Where, q (Heat flux) = Watt / m^2

h (Heat transfer coefficient) = Watt / m^2K.