# Churchillâ€“Bernstein Equation

## Description

The equation yields the surface averaged Nusselt number, which is used to determine the average convective heat transfer coefficient. Newton’s law of cooling can then be invoked to determine the heat loss or gain from the object, fluid and/or surface temperatures, and the area of the object, depending on what information is known.

Related formulas## Variables

N_{d} | surface averaged Nusselt number with characteristic length of diameter (dimensionless) |

Re_{d} | Reynolds number with the cylinder diameter as its characteristic length (dimensionless) |

Pr | Prandtl number (dimensionless) |