The temporal and spatial dynamics of cavitation bubble cloud growth and collapse in extracorporeal shock wave lithotripsy (ESWL) is studied experimentally. The first objective is obtaining reproducible cloud patterns experimentally and comparing them with FDTDcalculations. Second, we describe a method to modify the cavitation pattern by timing two consecutive pressure waves at variable delays. ...

In single-bubble sonoluminescence, an ultrasound-driven microbubble undergoes violent oscillations and converts part of the energy of the sound field into visible light. Since its discovery ten years ago, a consistent theory of the dynamics and stability of the bubble has been developed. The approach includes the dissociation of molecular gases inside the collapsing bubble to explain striking d...

Method: The presented EL method uses the open access software OpenFOAM to solve bubble dynamics with bubble interactions computed via Monte Carlo methods. The estimated bubble size distribution and the predicted hold-up are compared with experimental data and other simulative EE work with a reasonable consensus for both. Benchmarks with state of the art EE simulations shows that the EL approach...

We present an experimental analysis of the effects of gravity level on the formation and rise dynamics of bubbles. Experiments were carried out with millimeter-diameter bubbles in the hypergravity environment provided by the large-diameter centrifuge of the European Space Agency. Bubble detachment from a nozzle is determined by buoyancy and surface tension forces regardless of the gravity level...

Detailed measurements of bubble composition, dissolved gas concentrations, and plume dynamics were conducted during a 9-month period at a very intense, shallow (22-m water depth) marine hydrocarbon seep in the Santa Barbara Channel, California. Methane, carbon dioxide, and heavier hydrocarbons were lost from rising seep bubbles, while nitrogen and oxygen were gained. Within the rising seawater ...

The deposition of ultrasonic energy in tissue can cause tissue damage due to local heating. For pressures above a critical threshold, cavitation will occur, inducing a much larger thermal energy deposition in a local region. The present work develops a nonlinear bubble dynamics model to numerically investigate bubble oscillations and bubble-enhanced heating during focused ultrasound (HIFU) inso...

The influence of a continuous sound field on the first oscillation cycle and on the cavitation luminescence of a transient laser-induced bubble is investigated experimentally. The variation of the collapse phase is predicted with a simple numerical model and compared with experiment. Bubble dynamics is mainly influenced by three parameters: the phase of bubble generation, the size of the bubble...

We report a molecular dynamics study of homogeneous bubble nucleation in a Lennard-Jones fluid. The rate of bubble nucleation is estimated using forward-flux sampling (FFS). We find that cavitation starts with compact bubbles rather than with ramified structures, as had been suggested by Shen and Debenedetti (J. Chem. Phys. 1999, 111, 3581). Our estimate of the bubble-nucleation rate is higher ...

We provide a model of rational bubbles in a DNK framework. Entrepreneurs are heterogeneous in investment efficiency and face credit constraints. They can trade bubble assets to raise their net worth. The bubble assets command a liquidity premium and can have a positive value. Monetary policy affects the conditions for the existence of a bubble, its steady-state size, and its dynamics including ...

9 A surprising phenomenon witnessed by many is the sinking bubbles seen in a settling pint of 10 stout beer. Bubbles are less dense than the surrounding fluid so how does this happen? Previous 11 work has shown that the explanation lies in a circulation of fluid promoted by the tilted sides of the 12 glass. However, this work has relied heavily on computational fluid dynamics (CFD) simulations....