Viscous Dissipation Caused by a Sphere

Recent studies have led to a satisfactory solution to the problem of acoustic streaming in the vicinity of a sphere for s/a≪1, where s is the oscillation amplitude, and a is the radius of the sphere. The results of these studies have now been applied to the calculation of the inherent energy losses. The energies in the dc vortices and in the primary ac vortices have been computed, and it is shown that the energy in the former is negligible in comparison with the energy in the latter. The results are restricted to cases where s/a≪1, and a(ω/2ν)12≫1, where ν is the kinematic viscosity and ω is the frequency of oscillation.