Experimental and Numerical Study of Acoustic Streaming in a Cylindrical Enclosure

Acoustic streaming motion generated by finite-amplitude resonant oscillations in an air-filled two-dimensional cylindrical enclosure was experimentally studied and numerically simulated. The oscillatory flow field in the enclosure was created by the vibration of one end of the cylindrical resonator (L = 325 mm, R = 12.5 mm). The frequency of the wall vibration was chosen as f = 1062 Hz, such that the corresponding wavelength is equal to the length of the resonator. A standing wave was then generated in the closed tube. In the experiment, the flow field was visually studied by a smoke generator, He-Ne Laser and a digital camera. The pressure wave in the axial points was measured by a piezoresistive pressure transducer (Endvco #4428A). To simulate the flow field, the full compressible form of the Navier-Stokes equations in cylindrical coordinates was considered and solved by a highly accurate flux-corrected transport algorithm for convection terms and a central differencing scheme for the viscous and diffusive terms. In both of the experimental and numerical studies, outer acoustic streaming due to interaction of acoustic waves with viscous boundary layers was observed, and the effects of sound field intensity on the formation of streaming structures were studied.