A simplified finite element model for ultrasonic cleaning

Simplified models for ultrasonic cleaning are presented which require significantly less computational effort than the transient finite element analysis previously employed for this fluid—structure interaction problem. The analysis is simplified three ways: (1) by solving for the steady state frequency solution; (2) by assuming that the solid is rigid to scattered waves; and (3) by using an infinite boundary condition approximation in the finite element solution. When the wave is incident from the solid, estimating the force on contaminant particles using these techniques requires only one-thousandth the computational effort of a full transient analysis. When the wave is incident from the fluid, treating the solid as completely rigid gives essentially the same results at 0·1 and 1 GHz as treating the solid as rigid to scattered waves only. However, this analysis indicates that the force on the contaminant particle produced by a wave originating in the solid is less than one-seventh the force produced by a wave originating in the fluid.