Dynamics of a gas bubble near the aperture of a perforated concave rigid plate

Abstract

The dynamics of a gas bubble close to intact and perforated concave rigid plates located in unlimited liquid domain is studied using boundary element method combined with finite difference method. First, we examine the effect of bubble-plate distance on the behavior of the bubble near an intact plate. Next, for a perforated plate, we investigate the influence of bubble-hole distance and hole size on the bubble dynamics and provide the pressure field and velocity vectors of the surrounding liquid to better understand and interpret the results. It was found that in the case of intact plate there is only an inward high-speed liquid jet pointing to the plate. However, in the case of the perforated plate, depending on the values of bubble-hole distance and hole size there might be also a low-speed outward liquid jet pointing away from the plate. Three different bubble oscillation scenarios were found based on the relative values of the two parameters: bubble-hole distance and hole size. These sce-narios are: (I) two liquid jets, (II) an inward liquid jet pointing to the hole and (III) a fairly spherical bubble oscillation without induced jets.