Numerical and experimental investigation of the role of inertia on acoustic Rayleigh streaming in a standing waveguide

Abstract

International audienceRayleigh streaming is a mean flow generated by the interaction between a standing wave and a solid wall. In the case of a low amplitude wave inside a cylindrical resonator, the streaming pattern along a quarter wavelength is composed of two toroidal cells: An inner cell close to the tube wall and an outer cell in the core. In the present work the effect of inertia on Rayleigh streaming at high acoustic level is investigated numerically and experimentally. To this effect, time evolutions of streaming cells in the near wall region and in the resonator core are analyzed. For the analysis of the outer cell, an analogy with the lid-driven cavity in a cylindrical geometry is proposed. It is shown that the outer cell is distorted due to convection, but the previously observed emergence of an extra cell cannot be recovered. Inertial effects on the established streaming flow pattern are further investigated numerically by solving time averaged Navier-Stokes equations with an imposed acoustic source. Results are similar to those obtained from the lid-driven cavity simulations. Therefore inertial effects cannot be considered as responsible for the mutation of streaming at high acoustic levels