Stokes number
3393596
202525848
2008-04-01T12:18:14Z
131.175.20.16
<p>The '''Stokes number''', named after [[Irish people|Irish]] mathematician [[George Gabriel Stokes]], is a [[dimensionless number]] corresponding to the behavior of particles suspended in a fluid flow. Stokes number is defined as the ratio of the stopping distance of a particle to a characteristic dimension of the obstacle, or</p>
<p><center><math>Stk = \frac{\tau\,U_o}{d_c}</math></center></p>
where <math>\tau</math> is the relaxation time of the particle, <math>U_o</math> is the fluid velocity of the flow well away from the obstacle and <math>d_c</math> is the characteristic dimension of the obstacle. For <math>Stk\gg 1</math>, particles will continue in a straight line as the fluid turns around the obstacle therefore impacting on the obstacle. For <math>Stk\ll1</math>, particles will follow the fluid streamlines closely.
==References==
{{Reflist}}{{refbegin}}
* {{cite book |author=Fuks, N. A. |title=The mechanics of aerosols |publisher=Dover Publications |location=New York |year=1989 |pages= |isbn=0-486-66055-9 |oclc= |doi=}}
* {{cite book |author=Hinds, William C. |title=Aerosol technology: properties, behavior, and measurement of airborne particles |publisher=Wiley |location=New York |year=1999 |pages= |isbn=0-471-19410-7 |oclc= |doi=}}
{{refend}}
==External links==
* [http://www.iop.org/EJ/article/1367-2630/6/1/119/njp4_1_119.html Reynolds number scaling of particle clustering in turbulent aerosols]
[[Category:Dimensionless numbers]]
[[Category:Discrete-phase flow]]
{{fluiddynamics-stub}}
{{NonDimFluMech}}
[[ca:Nombre de Stokes]]
[[es:NĂºmero de Stokes]]
[[nl:Getal van Stokes]]