Numerical simulation of high-intensity standing wave fields

The numerical simulation of high-intensity ultrasound sources is considered based on a finite element scheme, which has been developed by the authors during the last years. Having previously dealt with pulsed devices, we here consider ultrasound sources operating in cw-mode. In this case additional effects due to the formation of nonlinear standing wave fields can be observed. First, we will demonstrate the validity of our simulation scheme by comparing numerical results with analytical data available for simple non-planar radiation problems. Next, plane nonlinear standing wave fields in a water filled tube are considered and simulation results are compared with measurements available in the literature. Acoustic streaming forces are calculated and the significance of the inclusion of nonlinear effects in the simulation is demonstrated. Finally, the sound field and the induced acoustic streaming forces of a high-intensity plane piston source are considered.