Nonlinear acoustic multicavitation with external ultrasound field in complex fluids: Numerical investigation

Abstract

Abstract The motivation behind employing nonlinear dynamics of acoustic multicavitation bubbles in complex fluids lies in their potential to enhance the efficiency of various fabrication processes of nanomaterials, such as polymers, wastewater treatment, food processing, and biomedical processes (i.e., histotripsy and biotissue systems). The study aims to focus mainly on the acoustic multicavitation dynamics under the impact of external fields such as shear stress, magnetic field, pressure due to surface tension, and electrical conductivity in N-dimensions of generalized Newtonian fluids (i.e., Newtonian, non-Newtonian, and viscoelastic fluids). This paper deals with the numerical simulation of the nonlinear dynamics of acoustic multicavitation bubbles in complex fluids of generalized Newtonian, N-dimensional fluids subjected to external fields. The interparticle interaction between the cavitation bubbles is taken into the formulation of the nonlinear dynamics of acoustic cavitation bubbles. The mathematical models of the nonlinear dynamics of acoustic multicavitation are formulated based on a continuity equation, a Cauchy equation, shear stress relations, and pressure relations due to interparticle interaction between the cavitation bubbles in N-dimensions. The obtained model (namely, the modified Rayleigh–Plesset equation of acoustic multicavitation bubbles) is computationally established on the Hb-spline collocation methodology in Newtonian, non-Newtonian, and viscoelastic fluids. From the analysis results, the increase in external fields of liquid electrical conductivity and magnetic field, decreases the nonlinear dynamics of acoustic multicavitation in generalized Newtonian fluids where the model prediction of illustrates that the collapse of multicavitation bubble dynamics is happening rapidly in the existence of magnetized forces and the electrical conductivity of a non-Newtonian fluid in N-dimensions. Acoustic cavitation bubble behavior and its phase portrait increase with an increment in the number of N-dimensions and a reduction in the number of microbubbles. The proposed prototype can determine the instantaneous acoustic of microcavities throughout their formation and identify various physical parameters that govern the microcavitation’s acoustic process, as well as the frequency of microcavitation formation. The stability of the solutions of the proposed model, which is solved by the Hb-Spline method, is investigated, discussed, and compared with results by the Runge–Kutta method.