Finite-element analysis of acoustic streaming generated between a bending transducer and a reflector through second-order approximated forces

Abstract

The simulation of acoustic streaming between a bending transducer and a reflector is discussed. Instead of full fluid analysis, the streaming is calculated from second-order approximated forces of acoustic streaming and static pressure originated by the nonlinear sound field. Sound field and fluid dynamics are simulated separately under finite-element harmonic and static analyses, respectively. Through two examples of streaming, the validity of the simulation method is verified. One is streaming excited between a disk vibrator and a reflector, and the other is streaming in an ultrasonic air pump. By comparing the calculated results with the measured ones in terms of the distribution of sound pressure and streaming, it is found that the present method can well simulate the streaming in the air layer.

Increase of holding force in near-field acoustic levitation of tabular object inserted between opposing vibration sources

“…The acoustic streaming U is assumed with incompressible fluid because it is sufficiently smaller than the velocity of sound in air. Therefore, the acoustic streaming U was obtained by solving incompressible fluid equations using the body force 29) expressed by…”

Finite element analysis of acoustic streaming in a Kundt tube with bended wall

“…Acoustic streaming is obtained as a solution of static-fluid velocity driven by this imaginary force. 34) Only fluid convection is considered among the fluid nonlinearities. The stationarity of both the acoustics and fluid dynamics is guaranteed even for single or a-few-iteration analysis.…”