Surface-induced yaw of a rotlet dipole
= Surface-induced yaw of a rotlet dipole
{title2=$\omega_z=3D/(128\pi\mu h^4)$}
For an axial <rotlet dipole> parallel to a flat free surface, its reflected image gives the displayed normal <vorticity> at height $h$. A spherical <torque>-free body responds with angular <velocity> $\omega_z/2$ and an elongated body also responds to strain. At constant height, self-propulsion plus yaw gives a circular path; the signed moment sets its handedness.