Question

Why heat transfer coefficient is function of velocity?

Answer 1

Answer:

Explanation:

I'll answer this question with a few logical formulaes that govern the convective heat transfer. So, what to wait for, let's begin:

Nu=h.L/k (Nusselt No. Relation)

=> h=Nu.K/L

But, Nu=f(Re,Pr) [Nusselt No. is function of Reynolds No. and Prandtl No. for forced convection case]

=> h=f(Re,Pr).K/L

But, Re=f(velocity) [Reynolds No. is function of velocity of fluid, for a particular case in which if we consider a fluid flowing through a pipe has contant density and viscosity. Also, the pipe diameter remains the same.]

=> h=f(velocity)

Hence, we can say that heat transfer coefficient is directly a function of velocity and is proportional to it. And so, heat transfer coefficient increase with the increase in the velocity of fluid.