Editing Strouhal number (section)

===Medical===
In the medical field, microrobots that use swimming motions to move may make micromanipulations in unreachable environments.

The equation used for a blood vessel:<ref name="Doutel, E."/>

:<math> \text{St} = \dfrac{fD}{V}</math>,

where,
: ''f'' = oscillation frequency of the microbot swimming motion
: ''D'' = blood vessel diameter
: ''V'' = unsteady viscoelastic flow

The Strouhal number is used as a ratio of the [[Deborah number]] (De) and [[Weissenberg number]] (Wi):<ref name="Doutel, E."/>

:<math> \text{St} = \dfrac{\text{De}}{\text{Wi}}</math>.

The Strouhal number may also be used to obtain the [[Womersley number]] (Wo). The case for blood flow can be categorized as an unsteady viscoelastic flow, therefore the Womersley number is<ref name="Doutel, E."/>

:<math> \text{Wo} = \sqrt{\dfrac{\pi}{2}*\text{Re}*\text{St}}</math>,

Or considering both equations,

:<math> \text{Wo} = \sqrt{\dfrac{\pi}{2}*\text{Re}*\dfrac{\text{De}}{\text{Wi}}}</math>.