Question

What is a cold wall case?

(a) Heat flowing from fluid to wall

(b) Heat flowing from wall to fluid

(c) Reducing temperature of upper wall

(d) Reducing temperature of lower wall

The question was posed to me by my school principal while I was bunking the class.

I need to ask this question from Couette Flow in chapter Numerical Techniques for Nonlinear Supersonic Flow, Elements of Hypersonic Flow, Couette and Poiseuille Flow of Aerodynamics

Answer 1

Right option is (a) Heat flowing from fluid to wall

The best I can explain: The two flat plates in case of a Couette flow is kept at different temperatures thus creating a temperature gradient. This results to heat transfer through the fluid at both upper and lower surfaces of the plate. When the heat flows from fluid to the wall it is known as cold wall case, and when the heat flows from the wall to the fluid, it is known as hot wall case.