Numerical Investigation of the Dynamics of Pressure Loading on a Solid Boundary from a Collapsing Cavitation Bubble

Abstract

The motivation behind this research lies in understanding the physical mechanism of cavitation erosion in compressible liquid flows, with applications in the field of aerospace, hydrodynamics, diesel injectors etc. As a consequence of collapsing vapor cavities in cavitating flow near solid boundaries, high pressure impact loads are generated. These pressure loads are believed to be responsible for the erosive damages on solid surface observed in most applications. For our investigation, the initial geometry is a single vapor bubble near a solid boundary collapsing due to the pressure difference between the bubble and surrounding liquid. The numerical approach employs a simplified homogenous mixture or 'single fluid' model with barotropic assumption in a fully compressible finite-volume fluid solver. The numerical method is validated against the well-known Rayleigh collapse of a pure 3D vapour bubble. It is then used for the simulation of a 2D vapour bubble collapsing in the proximity of a solid boundary placed at a specified distance from the centre of the bubble. The pressure loads are computed from the evolving dynamics of collapsing bubble near a solid boundary which can be used to determine the resulting surface deformation. The developed compressible cavitation solver in the CFD code 2 can efficiently model small and large scale cavitating structures in a fully resolved three dimensional flow.

Universal Piezo-Photocatalytic Wastewater Treatment on Realistic Pollutant Feedstocks by Bi4TaO8Cl: Origin of High Efficiency and Adjustable Synergy

“…39 However, it is difficult to fix the T 3 values since the actual pressure generated under sonication is vaguely reported in the range of 0.1−10 GPa for a single bubble collapse. 40 If we consider T 3 = 1 GPa, the calculated open-circuit voltage across the Bi 4 TaO 8 Cl nanoplates is about 4.0 V and so is the bandbending potential. Therefore, band-bending by 2.5 eV requires a pressure of 6 × 10 8 Pa, which can be tuned either by changing W 3 or e r , or d 33 (hence intrinsic polarization).…”

“…The e r of Bi 4 TaO 8 Cl has been considered as 150 . However, it is difficult to fix the T 3 values since the actual pressure generated under sonication is vaguely reported in the range of 0.1–10 GPa for a single bubble collapse . If we consider T 3 = 1 GPa, the calculated open-circuit voltage across the Bi 4 TaO 8 Cl nanoplates is about 4.0 V and so is the band-bending potential.…”