# Heat transfer coefficient

## Description

Heat flux or thermal flux is the rate of heat energy transfer through a given surface, per unit surface. The heat transfer coefficient or film coefficient, in thermodynamics and in mechanics is the proportionality coefficient between the heat flux and the thermodynamic driving force for the flow of heat. It is used in calculating the heat transfer, typically by convection or phase transition between a fluid and a solid.

Related formulas## Variables

h | Heat transfer coefficient (W/m^{2}*K) |

Q | Heat flux (W/m^{2}) |

T_{s} | Temperature of the solid surface (K) |

T_{f} | Temperature of the surrounding fluid area (K) |