Film temperature
In heat transfer and fluid dynamics, the film temperature (![T_f](/Images/godic/202501/13/ce01ae2615d6f8d01f44320a815c575f2747.png")
) is an approximation to the temperature of a fluid inside a convection boundary layer. It is calculated as the arithmetic mean of the temperature at the surface of the solid boundary wall (![T_w](/Images/godic/202501/13/00780ced1ceafac84227cedf5937719c2747.png")
) and the free-stream temperature (![T_\infty](/Images/godic/202501/13/373a6c2b1dc4983393fe0aa32237304c2747.png")
):