Heterogeneous bubble nucleation at surfaces has been notorious because of its irreproducibility. Here controlled multibubble surface cavitation is achieved by using a hydrophobic surface patterned with microcavities. The expansion of the nuclei in the microcavities is triggered by a fast lowering of the liquid pressure. The procedure allows us to control and fix the bubble distance within the b...

In this study, the cavitation effect induced by two charges in underwater explosions near free surfaces is numerical researched dimensional compressible multiphase fluids based on a four-equation system with phase transition model. The occurrence of generation, development, and collapse two-charge can be captured directly. detailed density, pressure, vapor volume fraction contours during intera...

The evolution of a cylindrical sulfur hexafluoride (SF6) bubble in the flow accelerated by nonuniform diffraction shock is investigated using density-based compressible OpenFOAM solver. generated from an initial planar with Mach number 2.2 rectangular barrier, and influence barrier height on gas analyzed detail both qualitatively quantitatively. results show that increasing height, becomes weak...

A model for bubble formation from a single submerged orifice is developed using the boundary-integral method. Since the flow field is assumed to be irrotational, potential-flow theory is used to predict the growth of the bubble. The effects of the surface tension and the liquid circulation around the bubble are included in the calculation. Predictions of bubble shape, chamber pressure and the e...

Two-phase bubble formation coupled with phase change at a submerged nozzle is studied theoretically. The whole bubble consists of a ®apor and a liquid phase. The inner ®apor phase is assumed to be surrounded by a thin condensate layer, in which the ®apor condenses partially as the two-phase bubble grows. The interface element approach is applied to describe the dynamics of bubble formation. The...

Bubble cloud collapse is one of the most destructive forms of cavitation. However, numerical modeling of this phenomenon is challenging and involves strong bubble dynamics, bubble-bubble, and bubble-wall interactions. Here we consider an initially spherical cloud near a rigid wall and treat the cloud bubbly mixture as a continuum and the bubbles in the cloud as discrete singularities. These two...

A discrete-bubble model that predicts the rate of oxygen transfer in diffused-bubble systems is evaluated. Key inputs are the applied gas flow rate and the initial bubble size distribution. The model accounts for changes in the volume of individual bubbles due to transfer of oxygen and nitrogen (and hence changing partial pressure), variation in hydrostatic pressure, and changes in temperature....

Surface cleaning using cavitation bubble dynamics is investigated numerically through modeling of bubble dynamics, dirt particle motion, and fluid material interaction. Three fluid dynamics models; a potential flow model, a viscous model, and a compressible model, are used to describe the flow field generated by the bubble all showing the strong effects bubble explosive growth and collapse have...

Medical ultrasound has shown great potential as a minimally invasive therapy technique. It can be used in areas such as histotripsy, thermal ablation, and administering medication. The success of these therapies is improved by the cavitation of microbubbles. This study evaluated the effect of varying the pressure amplitude on cavitation resonance frequency and the corresponding bubble size at t...