Numerical investigation of sonochemical reactors considering the effect of inhomogeneous bubble clouds on ultrasonic wave propagation

Numerical simulations are used to investigate the impact of different chamber configurations and process parameters on the sound intensity in a sonochemical reactor. In chemical processes, ultrasound may cause cavitation and increase reaction rates significantly. Therefore, quantifying the ultrasound field in such a device is of great interest in order to improve the reactor performance. Since not all details of the interaction between acoustic field, cavitation and chemical reactions are known, simulations may help to improve the understanding of the reactor characteristics. The results of different working assumptions for modelling of the wave propagation, attenuation of pressure due to cavitation bubbles and the influence of geometry are examined. The applied models are based on the linearised wave equation in the frequency domain with a suitable extension to account for nonlinear attenuation. The trends in the variation of the bubble volume fraction and pressure amplitude are investigated numerically as functions of the ultrasonic frequency and power.

► The acoustic field in a sonochemical reactor is analysed numerically.
► The effect of modelling cavitation on wave propagation is investigated.
► The simulations allow localisation of favourable regions of cavitation in the reactor.
► Optimal operating conditions for frequency and power of transducers are identified.