Biot Number

Written by Jerry Ratzlaff on . Posted in Dimensionless Numbers

Biot Number

Biot Number ( \(Bi\) ) (dimensionless number) is the ratio of internal thermal resistance of solid to fluid thermal resistance.  This is used for heat transfer between fluids and solids.

Biot Number FORMULA

\(\large{ Bi=\frac{hl_c}{k}  }\)               


\(\large{ Bi }\) = biot number

\(\large{ c_d }\) = diffusion coefficient

\(\large{ c_m }\) = mass transfer coefficient

\(\large{ h }\) = heat transfer coefficient

\(\large{ k }\) = thermal conductivity of the body

\(\large{ l_c }\) = characteristic length


Tags: Equations for Heat Transfer