Characterisation and improvement of a reference cylindrical sonoreactor

This paper describes theoretical and experimental methods for characterising the performance of a 25 kHz sonochemical reactor (RV-25), which is being developed as a reference facility for studying acoustic cavitation at the National Physical Laboratory (NPL). Field measurements, acquired in different locations inside the sonoreactor, are compared with finite element models at different temperatures, showing that relatively small temperature variations can result in significant changes in the acoustic pressure distribution (and consequent cavitation activity). To improve stability, a deeper insight into the way energy is transferred from the power supply to the acoustic field is presented, leading to criteria – based on modal analysis – to dimension and verify an effective temperature control loop. The simultaneous use of measurements and modelling in this work produced guidelines for the design of multi-frequency cylindrical sonoreactors, also described.