Question

How does velocity affect the coefficient of heat transfer?

Answer 1

QUESTION..

→How does velocity affect the coefficient of heat transfer??

ANSWER..

→Few logical formulaes that govern the convective heat transfer.

Nu=h.l/k (nusselt no relation)

=>h=Nu.k/l

But Nu=f(Re,Pr)

[Nusselt No. is function Reynolds no. and pramdtl 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...

This is the most easiest way I could have written .....