超声场中液体材料的空化和声流动力学研究进展

Power ultrasound can effectively control the heat and mass transfer processes in liquids due to its cavitation and acoustic streaming effects, leading to a broad application prospect in the field of material preparation. Due to the opacity of alloy melt, it is impossible to observe the ultrasonic process directly in experiment, and numerical simulation becomes an important method to fully analyze the propagation characteristics of ultrasonic and its effect on alloy solidification. This overview firstly summarizes the evolution of sound propagation equation from linear model to non-linear model and the modification mechanisms of ultrasonic power, sonotrode size, container shape and ultrasonic dimension on sound pressure and acoustic streaming. Besides, the numerical simulation results of cavitation dynamics in single and multiple bubble systems is introduced, including bubble instability mechanism, bubbles interaction and the effect of cavitation on the liquid pressure and temperature. Furthermore, by combining ultrasonic cavitation and acoustic streaming dynamics with metal solidification process, several macro-models and micro-models to simulate ultrasonic solidification is presented, and the mechanisms of ultrasonic cavitation and acoustic streaming on crystal nucleation growth, heat transfer and liquid flow are systematically summarized. Finally, a concise perspective is provided for its future advances.