Question

How do you increase heat transfer coefficient?

(a) By increasing Reynolds number

(b) By decreasing Reynolds number

(c) By increasing velocity

(d) By increasing Reynolds number and velocity

This question was addressed to me during an interview.

This is a very interesting question from Heat Transfer in Evaporators in section Evaporation of Food Processing Unit Operations

Answer 1

Right answer is (d) By increasing Reynolds number and velocity

The best explanation: To increase the heat transfer coefficient by increasing Reynolds number and velocity of fluid when it flows through a pipe. This is due to higher velocity increases turbulence, which in turn provides a more efficient radial transport of heat.