Blake Number

on . Posted in Dimensionless Numbers

Blake number, abbreviated as Bl, a dimensionless number, used in fluid dynamics to describe the ratio of inertial force and viscous force and is used in momentum transfer and flow through beds of solids.

 

Blake Number formula

\( B =   v \; \rho \; d_h \;/\; \mu \; \left( 1 - \epsilon \right)   \)
Symbol English Metric
\( Bl \) = Blake number \(dimensionless\)
\( v \) = velocity of fluid \(ft\;/\;sec\) \(m\;/\;s\)
\( \rho \)   (Greek symbol rho) = density of fluid \(lbm\;/\;ft^3\) \(kg\;/\;m^3\)
\( d_h \) = hydraulic diameter \( ft \) \( m \)
\( \mu \)  (Greek symbol mu) = dynamic viscosity of fluid \(lbf-sec\;/\;ft^2\) \( Pa-s \)
\( \epsilon \)   (Greek symbol epsilon) = void fraction \(dimensionless\)

 

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Tags: Force