Blake number

The Blake number in fluid mechanics is a nondimensional number showing the ratio of inertial force to viscous force. It is used in momentum transfer in general and in particular for flow of a fluid through beds of solids. It is a generalisation of the Reynolds number for flow through porous media.

Expressed mathematically the Blake number $B$ is:


 * $$B = \frac{u \rho D_h}{\mu ( 1-\epsilon)}$$

where


 * {| style="border:0px"


 * $&epsilon;$ || = || void fraction
 * $&mu;$ || = || dynamic viscosity
 * $&rho;$ || = || fluid density
 * $D_{h}$ || = || hydraulic diameter
 * $u$ || = || flow velocity
 * }
 * ᙭᙭᙭ || = || hydraulic diameter
 * ᙭᙭᙭ || = || flow velocity
 * }
 * }