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Lamb-Oseen vortex

In Fluid Mechanics, the Lamb-Oseen vortex models a line vortex that decays due to viscosity.

The mathematical model for the velocity in the θ direction in the Lamb-Oseen vortex is:

V_\theta\ (r) = \frac{\Gamma}{2\pi} \frac{1-e^{-\left (\frac{r}{r_c} \right )^2}}{r}

r = radius rc = Core radius of vortex Γ = Circulation contained in the vortex

An alternative definition is to use the peak tangential velocity of the vortex rather than the total circulation

V_\theta\left( r \right) =                         V_{\theta max} \left( 1 + \frac{0.5}{\alpha} \right)                         \frac{r_c}{r}                         \left[ 1 - \exp \left( - \alpha \frac{r^2}{{r_c}^2} \right)                         \right]

where α = 1.26 as used in Devenport et al in a 1996 Journal of Fluid Mechanics paper (vol 312, pp67-106).

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Lamb-Oseen_vortex". A list of authors is available in Wikipedia.
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