Dipolar velocity field of a localized eddy
= Dipolar velocity field of a localized eddy
{title2=$\mathbf u_{\rm far}=[3\mathbf n(\mathbf I\cdot\mathbf n)-\mathbf I]/(4\pi r^3)$}
A localized <vorticity> distribution with nonzero <hydrodynamic impulse> induces $\mathbf u\sim[3\mathbf n(\mathbf I\cdot\mathbf n)-\mathbf I]/(4\pi r^3)$. This <curl>-free exterior velocity can remain long-ranged even when the <vorticity> is localized. In a random ensemble it produces dipolar longitudinal and transverse correlation tails.