Question

What is the thermal boundary layer?

(a) T = 0.90Te

(b) T = 0.89Te

(c) T = 0.99Te

(d) T = 0.97Te

I have been asked this question in an interview.

This intriguing question comes from Boundary Layer Properties in division Boundary Layers, Laminar & Turbulent Boundary Layers, Navier Stokes Solutions of Aerodynamics

Answer 1

Correct answer is (c) T = 0.99Te

To elaborate: The flow temperature just like velocity varies within the boundary layer. It is a function of y – direction. The temperature ranges from Tw which is the temperature at the wall (y = 0) to T = 0.99Te at y = δt, where δt is the thermal boundary layer thickness. This variation of temperature is known as temperature profile.