Shock-induced collapse of a vapor nanobubble near solid boundaries. (September 2016)

• Record Type: Journal Article
• Authors: Magaletti, Francesco; Gallo, Mirko; Marino, Luca; Casciola, Carlo Massimo
• Is Part Of: International journal of multiphase flow. Volume 84(2016)
• Page Start: 34
• Page End: 45
• Publication Date: 2016-09
• Subjects: Confined cavitation -- Bubble collapse -- Shock–bubble interaction -- Diffuse interface model; Multiphase flow -- Periodicals; Écoulement polyphasique -- Périodiques; Multiphase flow; Periodicals; 620.1064
• DOI: 10.1016/j.ijmultiphaseflow.2016.02.012
• Languages: English
• ISSNs: 0301-9322

Abstract

Highlights: Shock-induced bubble collapse near solid walls performed using a phase field approach. The thermodynamically consistent model accounts for capillarity and phase change. Bubble rebound and shock wave emission described. Jetting phase observed for sufficiently large triggering shock intensity. Pressure peaks found to take place at shock emission and jet formation. Abstract: The collapse of a nano-bubble near a solid wall is addressed here exploiting a phase field model recently used to describe the process in free space. Bubble collapse is triggered by a normal shock wave in the liquid. The dynamics is explored for different bubble wall normal distances and triggering shock intensities. Overall the dynamics is characterized by a sequence of collapses and rebounds of the pure vapor bubble accompanied by the emission of shock waves in the liquid. The shocks are reflected by the wall to impinge back on the re-expanding bubble. The presence of the wall and the impinging shock wave break the symmetry of the system, leading, for sufficiently strong intensity of the incoming shock wave, to the poration of the bubble and the formation of an annular structure and a liquid jet. Intense peaks of pressure and temperatures are found also at the wall, confirming that the strong localized loading combined with the jet impinging the wall is a potential source of substrate damage induced by the cavitation.