Motion of a spherical body in a viscous suspension

Abstract

The problem of drag of an arbitrary-size solid sphere with its motion in a uniform monodispersed viscous suspension is considered in the Stokes approximation. The expression for the effective suspension viscosity is derived in the first approximation over the volume concentration of the viscous suspension. The coefficient before the concentration is found in the form of an explicit analytical function, which depends on the ratio of sizes of the dispersed particles and the body. The found coefficient coincides with Einstein’s result at the limit of “point” dispersed particles, the size of which is negligibly small compared with the size of the moving sphere, but can substantially differ from it in the case of finite-size particles.