Effect of rheological properties of materials on their treatment with ultrasonic cavitation

Abstract

In the research, we proved that the optimum level of energy is the basis for an effective treatment of materials using ultrasonic cavitation. The key energy parameters are the pressure at the contact zone of the cavitator and material, and the speed of the contact zone movement. The main objectives of our work were to investigate the changes in the pressure components and determine their values considering the rheological parameters and the parameters of the dynamic material and cavitator. To achieve the objectives, we researched the elastic and dissipative components of rheological properties and determined their functions depending on the parameters of ultrasonic vibrations. The research methodology was based on the use of the fundamentals of the classical theory of acoustics. The mathematical description of the process was done using a model system including an acoustic apparatus and environment; this model was made by the authors. We calculated dissipation with the equations for environment motion considering two different laws of dissipation-factor changes; this was the requirement of the new model system. We proposed a new mathematical model; the researched system of the acoustic apparatus and the environment was considered as a whole. So, the elastic and dissipative parameters of the system were regulated among themselves. The selected mechanism of the regulation parameters was a system in resonance, achieved with a high-quality process of cavitation with a minimum energy consumption. We found the analytical dependence for determining the dynamic pressure on the environment with the acoustic apparatus. These dependencies provided the basis for assessing the influence of rheological properties on the treatment process using ultrasonic cavitation. Keywords: material, rheological properties, ultrasonic cavitation, energy, pressure V pri~ujo~i raziskavi so avtorji dokazali, da je optimalni energijski nivo osnova za u~inkovito obdelavo materialov z ultrazvo~no kavitacijo. Klju~na energijska parametra sta tlak v kontaktni coni kavitatorja in materiala, ter hitrost gibanja kontaktne cone. Glavni cilj raziskave je bil dolo~iti njune vrednosti ob spreminjanju tla~nih komponent, z upo{tevanjem reolo{kih parametrov in parametrov dinamike materiala in kavitatorja. Da bi dosegli cilje raziskave, so avtorji raziskovali elasti~ne in disipacijske (izgubne) komponente reolo{kih lastnosti in dolo~ili njihove funkcijsko odvisne parametre ultrazvo~nih vibracij. Raziskovalna metodologija je temeljila na uporabi temeljev klasi~ne teorije akustike. Za matemati~ni opis procesa so avtorji uporabili lastni modelni sistem akusti~ni aparat -okolje. Izra~unali so disipacijo v ena~bah za gibanje okolja z dvema razli~nima zakonoma sprememb faktorjev disipacije; to je bila zahteva novega modelnega sistema. Avtorji so predlagali nov matemati~ni model; raziskovani sistem akusti~ni aparat -okolje, ki so ga obravnavali kot celoto. Tako elasti~ni kot disipacijski parametri sistema so med seboj samoregulirani. Izbrani mehanizem parametrov reg...

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