Magnetically Induced Nonlinear Multicavitation Dynamics Near a Rigid Wall in (MWCNT- SWCNT-CuO-TiO2-MgO) Penta-Hybrid Nanofluids: Investigation of Thermophysical Properties

This study analytically investigates the influence of an external magnetic field on the nonlinear dynamics of multicavitation bubbles interactions near a solid boundary within a dielectric-based penta-hybrid nanofluid. To develop a structurally engineered penta-hybrid nanofluid, single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) were dispersed as primary carbon-based constituents, contributing to enhanced thermal conductivity and cavitation resistance, and nanoparticles of copper oxide (CuO), titanium dioxide (TiO₂), and magnesium oxide (MgO) to synergistically enhance its thermal conductivity, rheological behavior, and magnetic response. The imposed magnetic field generates Lorentz forces that significantly suppress bubble growth and modify the local pressure gradients, deformation patterns, and trajectory patterns of the interacting bubbles. A mathematical nonlinear model based on an axial-symmetric Navier-Stokes framework was developed, combining electromagnetic body forces and boundary-induced hydrodynamic effects. Analytical solutions based on the modified Plesset-Zwick method describe the coupled bubble wall dynamics. Parametric analyses reveal that nanoparticle concentration, magnetic field strength, and wall proximity critically govern bubble stability, collapse intensity, and interaction forces. The results validate the proposed model against previous theoretical and experimental findings, offering new insights into the magnetic control of microbubble. The findings offer crucial insights into the controllable manipulation of microbubbles in magnetically sensitive nanofluids, with direct relevance to biomedical ultrasound applications, targeted drug delivery, and energy-efficient cooling technologies.