Theoretical calculation of the acoustic radiation force on layered cylinders in a plane standing wave—comparison of near- and far-field solutions

Abstract

In this work, the theory for the acoustic radiation force on cylinders in a standing wave is extended to the case of cylinders coated with a viscoelastic polymer-type layer and immersed in ideal compressible fluids. Moreover, two different expressions for the radiation force function Yst (which is the radiation force per unit cross-sectional surface and unit energy density) for elastic cylinders are compared. The first expression for the radiation force function is obtained on the basis of the far-field derivation approach; however, the second expression is obtained from the near-field solution. It is demonstrated that the computational differences are commensurate with the same result. In the second step, calculations for the radiation force function are performed for an elastic brass cylinder coated by a viscoelastic (sound absorptive) phenolic polymer layer for four thicknesses of the outer covering layer. Additional calculations are also performed to investigate the fluid-loading effect on the radiation force function curves. Some of the results for the radiation force can be relevant to the non-contact manipulation of coated tubular phantoms in space-related applications.