= No-slip image system of a normal Stokeslet
{title2=$S=-2Fd(\mathbf n\mathbf n-I/3),\quad\mathbf M=Fd^2\mathbf n/\mu$}
A normal point <force> $F\mathbf n$ at height $d$ above a plane with a <no-slip boundary condition> is balanced by an image <Stokeslet> $-F\mathbf n$, a <stresslet> of tensor strength $S$, and a <source dipole> of moment $\mathbf M$ at the reflected point. Here the stresslet convention is $u_i=-S_{jk}\partial_kG_{ij}$, with $G$ the free-space Stokes tensor. Substitution on the plane cancels both normal and tangential <velocity>. The original and image forces cancel their $r^{-1}$ terms, while the image stresslet cancels the remaining $r^{-2}$ force-dipole term; the generic fixed-angle far field is $O(r^{-3})$.
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