scholarly journals Effects of air chemistry and stiffened EOS of air in numerical simulations of bubble collapse in water

2017 ◽  
Vol 2 (5) ◽  
Author(s):  
J. Zhang ◽  
T. L. Jackson ◽  
A. M. D. Jost
Keyword(s):  
Numerical Simulations ◽  
Bubble Collapse ◽  
Air Chemistry

313 Numerical Simulations for Matter Transport Associated with Bubble Collapse

2011 ◽  
Vol 2011.86 (0) ◽  
pp. _3-13_
Author(s):  
Kenshirou KUZUTANI ◽  
Hiroyuki TAKAHIRA ◽  
Yoshinori JINBO
Keyword(s):  
Numerical Simulations ◽  
Bubble Collapse ◽  
Matter Transport

scholarly journals Numerical and Experimental Study of the Interaction of a Spark-Generated Bubble and a Vertical Wall

2010 ◽  
Author(s):  
Arvind Jayaprakash ◽  
Georges Chahine ◽  
Chao-Tsung Hsiao
Keyword(s):  
Numerical Simulations ◽  
High Speed ◽  
Linear Time ◽  
Numerical Models ◽  
Vertical Wall ◽  
Bubble Collapse ◽  
Small Scale ◽  
Liquid Jet ◽  
Numerical Predictions ◽  
Jet Characteristics

An understanding of the fundamental mechanisms involved in the interaction between cavitation bubbles and structures is of importance for many applications involving cavitation erosion. Generally, the final stage of bubble collapse is associated with the formation of a high-speed reentrant liquid jet directed towards the solid surface. Local forces associated with the collapse of such bubbles can be very high and can exert significant loads on the materials. This formation and impact of liquid jet is an area of intense research. Under some conditions the presence of gravity and other nearby boundaries and free surfaces alters the jet direction and need to be understood, especially that in the laboratory, small scale tests in finite containers have these effects inherently present. In this work, experiments and numerical simulations of the interaction between a vertical wall and a bubble were carried out using Dynaflow’s three-dimensional code, 3DynaFS_Bem©, which models the unsteady dynamics of a liquid flow including the presence of highly non-linear time evolving gas-liquid interfaces. The numerical predictions were validated using scaled experiments carried out using spark generated bubbles. These spark bubble tests produced high fidelity test data that properly scale the fluid dynamics as long as the geometric non-dimensional parameters, gravity and time are properly scaled. The use of high speed cameras allowing framing rates as high as 50,000 frames per second to photograph the bubbles produced high quality observations of bubble dynamics including clear visualizations of reentrant jet formation inside the bubble. Such observations were very useful in developing and validating the numerical models. The cases studied showed very good correlation between the numerical simulations and the experimental observations and allowed development of predictive rules for the re-entrant jet characteristics, including jet angle and various definitions of the jet speed.

scholarly journals Numerical and Experimental Study of the Interaction of a Spark-Generated Bubble and a Vertical Wall

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Arvind Jayaprakash ◽  
Chao-Tsung Hsiao ◽  
Georges Chahine
Keyword(s):  
Numerical Simulations ◽  
High Speed ◽  
Numerical Models ◽  
Vertical Wall ◽  
Bubble Collapse ◽  
Small Scale ◽  
Liquid Jet ◽  
Numerical Predictions ◽  
Highly Nonlinear ◽  
Jet Characteristics

An understanding of the fundamental mechanisms involved in the interaction between bubbles and structures is of importance for many applications involving cavitation erosion. Generally, the final stage of bubble collapse is associated with the formation of a high-speed reentrant liquid jet directed toward the solid surface. Local forces associated with the collapse of such bubbles can be very high and can exert significant loads on the materials. This formation and impact of liquid jet is an area of intense research. Under some conditions, the presence of gravity and other nearby boundaries and free surfaces alters the jet direction and need to be understood, especially that in the laboratory, small scale tests in finite containers have these effects inherently present. In this work, experiments and numerical simulations of the interaction between a vertical wall and a bubble are carried out using Dynaflow’s three-dimensional code, 3DYNAFS-BEM, which models the unsteady dynamics of a liquid flow including the presence of highly nonlinear time evolving gas-liquid interfaces. The numerical predictions were validated using scaled experiments carried out using spark generated bubbles. These spark bubble tests produced high fidelity test data that properly scale the fluid dynamics as long as the geometric nondimensional parameters, gravity and time are properly scaled. The use of a high speed camera allowing framing rates as high as 50,000 frames per second to photograph the bubbles produced high quality observations of bubble dynamics including clear visualizations of the reentrant jet formation inside the bubble. Such observations were very useful in developing and validating the numerical models. The cases studied showed very good correlation between the numerical simulations and the experimental observations and allowed development of predictive rules for the re-entrant jet characteristics, including jet angle, jet speed, and various geometric characteristics of the jet.

scholarly journals Non-Spherical Collapse of an Air Bubble Subjected to a Lithotripter Pulse

2007 ◽  
Author(s):  
Eric Johnsen ◽  
Tim Colonius ◽  
Wayne Kreider ◽  
Michael R. Bailey
Keyword(s):  
Numerical Simulations ◽  
Solid Surface ◽  
Cavitation Bubble ◽  
Functional Dependence ◽  
Free Field ◽  
Bubble Collapse ◽  
Shockwave Lithotripsy ◽  
Stone Surface ◽  
Air Bubble ◽  
Spherical Collapse

In order to better understand the contribution of bubble collapse to stone comminution in shockwave lithotripsy, the shock-induced and Rayleigh collapse of a spherical air bubble is investigated using numerical simulations, and the free-field collapse of a cavitation bubble is studied experimentally. In shock-induced collapse near a wall, it is found that the presence of the bubble greatly amplifies the pressure recorded at the stone surface; the functional dependence of the wall pressure on the initial standoff distance and the amplitude are presented. In Rayleigh collapse near a solid surface, the proximity of the wall retards the flow and leads to a more prominent jet. Experiments show that re-entrant jets form in the collapse of cavitation bubbles excited by lithotripter shockwaves in a fashion comparable to previous studies of collapse near a solid surface.

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