title: Fast acoustic streaming in standing waves: generation of an additional outer streaming cell.
abstract: Rayleigh streaming in a cylindrical acoustic standing waveguide is studied both experimentally and numerically for nonlinear Reynolds numbers from 1 to 30 [Re(NL)=(U0/c0)(2)(R/δν)(2), with U0 the acoustic velocity amplitude at the velocity antinode, c0 the speed of sound, R the tube radius, and δν the acoustic boundary layer thickness]. Streaming velocity is measured by means of laser Doppler velocimetry in a cylindrical resonator filled with air at atmospheric pressure at high intensity sound levels. The compressible Navier-Stokes equations are solved numerically with high resolution finite difference schemes. The resonator is excited by shaking it along the axis at imposed frequency. Results of measurements and of numerical calculation are compared with results given in the literature and with each other. As expected, the axial streaming velocity measured and calculated agrees reasonably well with the slow streaming theory for small ReNL but deviates significantly from such predictions for fast streaming (ReNL>1). Both experimental and numerical results show that when ReNL is increased, the center of the outer streaming cells are pushed toward the acoustic velocity nodes until counter-rotating additional vortices are generated near the acoustic velocity antinodes.
authors: LIMSI-CNRS UPR 3251, Bât. 508 rue John Von Neumann, Campus Univ. Paris Sud, 91403 Orsay, France.
authors: Ida
authors: I
authors: Reyt
authors: Virginie
authors: V
authors: Daru
authors: Hélène
authors: H
authors: Bailliet
authors: Solène
authors: S
authors: Moreau
authors: Jean-Christophe
authors: JC
authors: Valière
authors: Diana
authors: D
authors: Baltean-Carlès
authors: Catherine
authors: C
authors: Weisman
mesh_terms: D000162:Acoustics; D000388:Air; D001274:Atmospheric Pressure; D003198:Computer Simulation; D017078:Laser-Doppler Flowmetry; D009038:Motion; D017711:Nonlinear Dynamics; D009716:Numerical Analysis, Computer-Assisted; D013016:Sound; D013997:Time Factors; D014732:Vibration