Analysis of doublet bubble dynamics near a rigid wall in ferroparticle nanofluids

Abstract

This study aims to characterize the interaction of doublet bubbles growing near a solid wall in ferroparticle nanofluids. Accordingly, we analyzed the behavior of spherical bubbles near a rigid wall considering liquid compressibility of suspended ferro-nanoparticles. In addition to the interaction effect between two bubbles, we considered the rigid wall forces and thermophysical configurations of the particles in nanofluids to understand the bubble growth. The equation of motion of the doublet bubbles was formulated based on the continuity equation, Euler equation, wave equation, and thermophysical configurations of the particles in nanofluids. Subsequently, the developed model was analytically solved by modifying the Plesset–Zwick technique. Throughout the bubble growth, we examined the thermal effects on the cavitation bubble dynamics, such as the distance between the interacting bubbles, vertical distance between the bubble center and rigid wall, and ferro-nanoparticle volume concentration. The analysis results revealed that the bubble growth was directly proportional to the Jacob number and thermal diffusivity, and inversely proportional to the distance between the boundary rigid wall and bubble center. Furthermore, it can be deduced from the results that the presence of the wall significantly influenced the bubble growth and made a significant deviation between the moving velocities of the interfaces both near and far from the wall. Ultimately, the phenomenon was physically interpreted based on the theory of bubble dynamics, and the water pressure induced by the bubble growth was estimated. The results were well aligned with the theoretical and experimental results from previous studies.