# Heat Transfer Coefficient

Written by Jerry Ratzlaff on . Posted in Thermodynamics

Heat transfer coefficient, abbreviated as h, also known as film coefficient or film effectiveness, is the convective heat transfer between a solid surface and the fluid around it.

### Heat Transfer Coefficient formula

$$\large{ h = \frac { Q" }{\Delta T} }$$

$$\large{ h=\frac{ Nu \; k }{ l_c } }$$     (Nusselt number)

Where:

$$\large{ h }$$ = heat transfer coefficient

$$\large{ l_c }$$ = characteristic length

$$\large{ Q" }$$ = heat flux

$$\large{ Nu }$$ = Nusselt number

$$\large{ \Delta T }$$ = temperature differential between the solid surface and surrounding area

$$\large{ k }$$ = thermal conductivity