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:

$B=\frac{u\rho D_h}{\mu (1-ϵ)}$

where

ε	=	void fraction
μ	=	dynamic viscosity
ρ	=	fluid density
Dh	=	hydraulic diameter
u	=	flow velocity

External links

• Tomas, J. (2010). "Mechanical Process Engineering – Particle Technology". Otto von Guericke University of Magdeburg. http://www.uni-magdeburg.de/ivt/mvt/englisch/Vorlesung/Lecture_MPE/Fig_MPE_4.pdf. Retrieved 11 February 2011.