Modelling and experimental investigation into cavity dynamics and cavitational yield: influence of dual frequency ultrasound sources

Modelling of a dual frequency ultrasonic reactor has been carried out to understand the effect of introducing a second wave on the cavity dynamics as compared to a single sound wave. The effect of the second wave of same and/or different frequency on the chemical yields has also been investigated experimentally. The introduction of a second sound wave results in better distribution of the cavitational activity in the reactor resulting in uniform yields, minimising the formation of standing waves and more effective utilisation of the reactant volume and dissipated sound energy. Also the energy efficiency of the dual frequency sound wave system is twice than that obtained for the single sound wave. The modelling studies indicate that the introduction of the second sound wave should be without any change in frequency with respect to the first wave in order to obtain maximum cavitational effects and hence resulting in higher chemical yields. (C) 2002 Elsevier Science Ltd. All rights reserved.