Acoustic streaming in liquids

Abstract

It has been suggested by Eckart (1948), Liebermann (1949) and others that measurement of acoustic streaming in a fluid provides an independent means of evaluating the ratio of the second coefficient of viscosity to the coefficient of shear viscosity. Arguments are put forward here to support the view (Nyborg 1953) that the streaming velocity is directly dependent on the coefficient of sound absorption. The second coefficient of viscosity influences the velocity of streaming only through its relationship to the coefficient of sound absorption. It is concluded that measurements of streaming velocity do not yield information about the second coefficient of viscosity other than may be obtained from the direct measurement of sound absorption. The theory of streaming based on the gradient of radiation pressure has been established quantitatively by a solution of the Navier-Stokes equations. A description is given of a method of determining the sound-absorption coefficient of a liquid from measurements of the velocity of streaming, and some typical results are stated.