Dynamics of a sphere with inhomogeneous slip boundary conditions in Stokes flow.
The dynamic resistance of a sphere with a general inhomogeneous slip boundary condition is analyzed in Newtonian unbounded uniform flow at low Reynolds number. The boundary condition is treated as a perturbation to a homogeneous sphere, assuming that the slip length magnitude b is much smaller than the sphere radius a . To first order, the effect of inhomogeneous slip is the same as that of a radial deformity of magnitude b . Full resistance tensors are presented and the dynamics of a hemispherical inhomogeneous sphere, such as a Janus particle, are explicitly calculated.
Willmott
Geoff
G
Industrial Research Limited, 69 Gracefield Road, Lower Hutt, New Zealand. g.willmott@irl.cri.nz