Numerical simulations of bubble dynamics in laser lithotripsy (Conference Presentation)

2020 ◽  
Author(s):  
Steven Peng
Keyword(s):  
Numerical Simulations ◽  
Bubble Dynamics ◽  
Laser Lithotripsy

Direct Numerical Simulations of Micro-Bubble Expansion in Gas Embolotherapy

2004 ◽  
Vol 126 (6) ◽  
pp. 745-759 ◽  
Author(s):  
Tao Ye ◽  
Joseph L. Bull
Keyword(s):  
Numerical Simulations ◽  
Bubble Dynamics ◽  
Moving Boundary ◽  
Vessel Diameter ◽  
Ideal Gas ◽  
Direct Numerical Simulations ◽  
Operating Conditions ◽  
Droplet Vaporization ◽  
Potential Development ◽  
Micro Bubble

We are currently developing a novel gas embolotherapy technique that involves the selective, acoustic vaporization of liquid perfluorocarbon droplets in or near a tumor as a possible treatment for cancer. The resulting bubbles can then stick within the tumor vasculature to occlude blood flow and “starve” the tumor. The potential development of high stresses during droplet vaporization is a major concern for safe implementation of this technique. No prior study, either experimentally or theoretically, addresses this important issue. In this work, the acoustic vaporization procedure of the therapy is investigated by direct numerical simulations. The nonlinear, multiphase, computational model is comprised of an ideal gas bubble surrounded by liquid inside a long tube. Convective and unsteady inertia, viscosity, and surface tension affect the bubble dynamics and are included in this model, which is solved by a novel fixed-grid, sharp-interface, moving boundary method. We assess the potential for flow-induced wall stresses to rupture the vessel or damage the endothelium during vaporization under a range of operating conditions by varying dimensionless parameters—Reynolds, Weber, and Strouhal numbers, inertial energy and initial droplet size. It is found that the wall pressure is typically highest at the start of the bubble expansion, but the maximum wall shear stress occurs at a later time. Smaller initial bubble diameters, relative to the vessel diameter, result in lower wall stresses.

Numerical and Experimental Investigations of the Cavitating Flow in a Centrifugal Pump Impeller

2002 ◽  
Author(s):  
Moritz Frobenius ◽  
Rudolf Schilling ◽  
Jens Friedrichs ◽  
Gu¨nter Kosyna
Keyword(s):  
Numerical Simulations ◽  
Centrifugal Pump ◽  
Bubble Dynamics ◽  
Cavitating Flow ◽  
Experimental Investigations ◽  
Pump Impeller ◽  
Pump Head ◽  
Flow Through ◽  
Technical University ◽  
Centrifugal Pump Impeller

This paper presents numerical simulations and experimental investigations of the cavitating flow through a centrifugal pump impeller of low specific speed. The experimental research was carried out at the Pfleiderer-Institute of the Technical University of Braunschweig, while the numerical simulations were performed at the Institute for Hydraulic Machinery and Plants at the Technical University of Munich (LHM). The cavitation model used is based on bubble dynamics and is able to describe the complicated and transient growth and collapse of the cavitation bubbles. The model has been implemented in the 3D CFD-code CNS3D developed at the LHM. The CNS3D-code has been applied to simulate the cavitating flow through a centrifugal pump impeller. The computed pump head, incipient NPSH and three-percent head drop are compared to the experimental data. Also the pressure distributions measured on the blades are compared with the computed ones. Finally, the numerically investigated void fraction distributions are shown in comparison with pictures of the cavitation zones on the blade.

A Study of Cavitation Bubble Temperatures in Room Temperature Ionic Liqiud

2013 ◽  
Vol 718-720 ◽  
pp. 209-213
Author(s):  
Yue Tao Yang ◽  
Bin Gao ◽  
Xiao Jun Liu ◽  
Shu Yi Zhang
Keyword(s):  
Numerical Simulations ◽  
Cavitation Bubble ◽  
Room Temperature ◽  
Bubble Dynamics ◽  
Liquid Surface ◽  
Methyl Radical ◽  
Bubble Dynamic ◽  
Point Of Interest ◽  
Liquid Surface Tension ◽  
The Difference

Room temperature ionic liquids (RTIL) have been developed to a central point of interest in both academia and industry. RTIL is non-volatile, thermally stable and non-flammable solvent. These properties can offer a green opportunity for sonochemical reactions. In this work, the cavitation bubble temperatures have been measured using methyl radical recombination (MRR) method. The temperatures measured in ImPF6 are in the range of 3000 4000 K. Additionally, based on the bubble dynamic equation with the consideration of liquid surface tension, viscosity and radiative resistance, numerical simulations have been carried out to investigate the cavitation bubble dynamics. The difference of the temperatures obtained from the experiment and numerical simulations has been interpreted.

A Bubble Dynamics Based Approach to the Simulation of Cavitation in Lubricated Contacts

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Thomas Geike ◽  
Valentin L. Popov
Keyword(s):  
Numerical Simulations ◽  
Experimental Evidence ◽  
Reynolds Equation ◽  
Bubble Dynamics ◽  
Simulation Models ◽  
Compressible Fluids ◽  
Fluid Film ◽  
Tensile Stresses ◽  
Lubricated Contacts

The negative squeeze lubrication problem is investigated by means of numerical simulations that account for the dynamics of vaporization. The model is based on bubble dynamics, governed by the Rayleigh–Plesset equation, and the Reynolds equation for compressible fluids. Unlike most existing simulation models our model can predict tensile stresses in the fluid film prior to its rupture, which is in accordance with experimental evidence.

scholarly journals A model for the effect of bulk liquid viscosity on cavitation bubble dynamics

2017 ◽  
Vol 19 (31) ◽  
pp. 20635-20640 ◽  
Author(s):  
Yang Shen ◽  
Kyuichi Yasui ◽  
Tong Zhu ◽  
Muthupandian Ashokkumar
Keyword(s):  
Experimental Data ◽  
Numerical Simulations ◽  
Cavitation Bubble ◽  
Bubble Dynamics ◽  
Single Bubble ◽  
Bulk Liquid ◽  
Liquid Viscosity ◽  
Single Bubble Dynamics ◽  
Theoretical Results

The effect of bulk liquid viscosity on single bubble dynamics has been investigated using numerical simulations. The theoretical results obtained are supported by the published experimental data.

Cavitation bubble dynamics during thulium fiber laser lithotripsy

2016 ◽  
Author(s):  
Luke A. Hardy ◽  
Joshua D. Kennedy ◽  
Christopher R. Wilson ◽  
Pierce B. Irby ◽  
Nathaniel M. Fried
Keyword(s):  
Fiber Laser ◽  
Cavitation Bubble ◽  
Bubble Dynamics ◽  
Laser Lithotripsy ◽  
Thulium Fiber Laser

scholarly journals Bubble Dynamics in Laser Lithotripsy

2015 ◽  
Vol 656 ◽  
pp. 012004 ◽  
Author(s):  
Milad Mohammadzadeh ◽  
Julian Martinez Mercado ◽  
Claus-Dieter Ohl
Keyword(s):  
Bubble Dynamics ◽  
Laser Lithotripsy
Sign in / Sign up

Export Citation Format

Share Document