Motion of a spherical particle in a viscous nonisothermal fluid

The Stokes and Hadamard-Riabouchinsky formulas are generalized to the case of steady motion of a solid spherical particle or drop in an incompressible fluid whose viscosity depends exponentially on the temperature. It is shown that for finite temperature differences between the surface of the particle and the region far from it the drag is determined by an effective viscosity with value close to the geometric mean of the viscosity on the surface of the particle and far from it.