Characteristics of the bubble-induced pressure, force, and impulse on a rigid wall

Abstract

When a bubble collapses near a rigid wall, a localized area of high pressure is generated on the wall. In the present study, experiments are carried out to record the dynamics of cavitation bubbles near a rigid wall and the corresponding numerical simulations are performed using computational fluid dynamics. The bubble expansion, contraction, collapse, jet formation, and rebound observed in the numerical simulations are in good agreement with the experimental results. Thereafter, the influence of the stand-off parameter γ on the bubble-induced pressure, force, and impulse on a rigid wall is quantitatively studied. The peak value of the initial shock wave is higher than that generated by the bubble collapse. Nevertheless, the bubble pulse and jet impact are superimposed, resulting in a much longer and stronger impulse than that of the initial shock wave. The impulse increases as γ decreases in the initial shock wave stage. However, this is not the case in the bubble collapse stage. For different ranges of the pressure integration, the maximum impulse caused by the bubble collapse occurs at a moderate value of γ. The findings reported in this paper provide a reference for cavitation- or bubble-related applications.