Modeling of Focused Ultrasound Propagation in Water Towards a Solid Target and Comparisons to Experimental Observations on Ultrasonic Cavitation

A numerical model has been developed for focused ultrasound propagation in water towards a solid target, for which the previous modeling work in the literature has been limited. The model predications are reasonably consistent with experimental observations on the cavitation region size at the target surface in the given ultrasound transducer power range, which has provided a verification of the model. The model calculations show that the ultrasound-induced peak negative pressure is highly spatially non-uniform on the side surface of a studied cylindrical target under the investigated conditions. This implies that to uniformly peen the target with focused ultrasonic cavitation peening, a special process design and/or parameter selection may be needed, for which the developed model may provide a useful guiding tool.