C. 43. 1, 2012 39 Mathematical model and similarity parameter of cavitation in sonoreactors S. D. Shestakov, A. E. Krasnov Moscow State University of Technologies and Management, 73 Zemlyanoy Val, Moscow, 109004, Russia E-mail: sdsh@mail.ru P. A. Gorodishchensky Ultratekhnika-SI, Ltd, 26 Arkhangelsk highway, Severodvinsk, 164500, Russia E-mail: tech_ultra@mail.ru It is shown that cavitation processes in liquids have a physical similarity with the identical chemical and physical properties at identical external environments in sonoreactors of different sizes with sources of acoustic fluctuations of different intensity. <...> A cavitation power can be estimated with help of the similarity criterion. <...> A criterion estimation allows to execute the engineering design and to predict the technical characteristics of sonoreactors for using in applied purposes. <...> Приведено описание этого критерия и эксперимента подтверждающего его адеквшпность. <...>