Weissenberg number

Physical key figure
Surname	Weissenberg number
Formula symbol	${\displaystyle {\mathit {Wi}}}$
dimension	dimensionless
definition	${\displaystyle {\mathit {Wi}}={\dot {\gamma }}\lambda }$
${\displaystyle \lambda }$ Relaxation time ${\displaystyle {\dot {\gamma }}}$ Shear rate
Named after	Karl Weissenberg
scope of application	Viscoelasticity

The Weissenberg number , named after the physicist and rheologist Karl Weissenberg , is a dimensionless number used to describe the viscoelastic behavior of fluids . Because of its similarity to the Deborah number , the Weissenberg number is often used in conjunction with it. ${\displaystyle {\mathit {Wi}}}$

The Weissenberg number is the product of the shear rate and relaxation time : ${\displaystyle {\dot {\gamma }}}$ ${\displaystyle \lambda }$

${\displaystyle {\mathit {Wi}}={\dot {\gamma }}\lambda }$

Individual evidence

1. ^ Nhan Phan-Thien: Understanding Viscoelasticity . Springer Science & Business Media, 2002, ISBN 3-540-43395-3 , pp. 63 ( limited preview in Google Book search).