The mean force acting on a small body in an axisymmetric sound field in a real medium (Q1097133)

A solution in the quadratic approximation is found for the problem of the mean force acting on a spherical body which is small in comparison with the length of the sound wave, located in an axisymmetric sound field in a real (viscous and heat-conducting) medium, with allowance for the dependence of the coefficient of dynamic viscosity on the temperature. It is shown that the solution of this problem is connected with the consideration of dipole acoustic flows which arise around a body in such a medium. The stresses created by these flows are not cancelled in integration over the surface of a body and thereby make a contribution to the mean force acting on it. In the formation of dipole acoustic flows it is not only the viscosity of the medium which is important, but also its thermal conductivity, and in addition the dependence of the coefficient of dynamic viscosity on the temperature. Consequently, the correct treatment of the contributions to the mean force from each of these effects is impossible without allowing for the dipole acoustic flows.