Effect of stand-off distance and spatial resolution on the pressure impact of near-wall vapor bubble collapses

TL;DR

This study uses numerical simulations to analyze how stand-off distance and spatial resolution affect cavitation bubble collapse near walls, revealing their impact on pressure and damage mechanisms.

Contribution

It introduces a detailed numerical analysis of cavitation bubble collapse near walls, highlighting the effects of stand-off distance and grid resolution on collapse dynamics and pressure peaks.

Findings

Stand-off distance significantly influences collapse behavior and wall pressure.

Main collapse features are captured even at coarse resolutions.

Peak pressures are highly resolution-dependent.

Abstract

We consider the collapse behavior of cavitation bubbles near walls under high ambient pressure conditions. Generic configurations with different stand-off distances are investigated by numerical simulation using a fully compressible two-phase flow solver including phase change. The results show that the stand-off distance has significant effects on collapse dynamics, micro-jet formation, rebound, and maximum wall pressure. A relation between cavitation induced material damage and corresponding collapse mechanisms is obtained from pressure-impact data at the wall. We analyze the resolution dependence of collapse and rebound and the observed maximum pressure distributions. The comparison of the results on six different grid resolutions shows that main collapse features are already captured on the coarsest resolution, while the peak pressures are strongly resolution dependent.