Investigation of ultrasonic pressure distribution in a sonoreactor and a washing tank by FEM simulation

摘要

The aim of this study is to investigate the ultrasonic pressure distribution in a sonoreactor and an ultrasonic washing tank by finite element method (FEM) by taking into account the coupling effect between the acoustic pressure in water and the mechanical vibration of the solid structure. To examine the ultrasound intensity distribution in a sonoreactor with a fixed volume of water, the ultrasonic pressure distribution at different L values, which was the distance between the tip of the ultrasound probe and the bottom of the reactor inner wall, was simulated. The ultrasound intensity distribution was then calculated based on the acoustic pressure distribution obtained from the FEM simulation. The validity of the computer simulation was evaluated by comparing the ultrasound intensity distributions in the sonoreactor at two different L values with the result of a microbial inactivation test conducted in the same sonoreactor for each L value when treated by mano-thermo-sonication in a batch operation. The acoustic pressure field between two transducer boxes in a custom-made ultrasound-assisted washing tank was simulated, which was then compared with the result of an erosion test with aluminum foils. A relatively good agreement was achieved between the FEM simulation and the pitting patterns formed on the aluminum foils caused by cavitation activities. With the current design of the ultrasound-assisted washing tank, both the simulation and erosion test showed that the ultrasound field distribution between two transducer boxes in the washing tank was relatively uniform.