scholarly journals A Numerical Study of the Formation of a Conical Cavitation Bubble Structure at Low Ultrasonic Frequency

2015 ◽  
Vol 70 ◽  
pp. 1070-1073 ◽  
Author(s):  
C. Vanhille ◽  
C. Campos-Pozuelo ◽  
C. Granger ◽  
B. Dubus
Keyword(s):  
Cavitation Bubble ◽  
Numerical Study ◽  
Ultrasonic Frequency ◽  
Bubble Structure

Numerical Study on the Growth and Collapse of a Cavitation Bubble inside a Rigid Cylinder with a Compliant Coating

2014 ◽  
Vol 875-877 ◽  
pp. 1194-1198
Author(s):  
Fardin Rouzbahani ◽  
M.T. Shervani-Tabar
Keyword(s):  
Integral Equation ◽  
Boundary Integral Equation ◽  
Cavitation Bubble ◽  
Numerical Study ◽  
Finite Difference Methods ◽  
Life Time ◽  
Integral Equation Method ◽  
Boundary Integral ◽  
Compliant Coating ◽  
Rigid Cylinder

In this paper, growth and collapse of a cavitation bubble inside a rigid cylinder with a compliant coating (a model of humans vessels) is studied using Boundary Integral Equation and Finite Difference Methods. The fluid flow is treated as a potential flow and Boundary Integral Equation Method is used to solve Laplaces equation for velocity potential. The compliant coating is modeled as a membrane with a spring foundation. The effects of the parameters describing the flow and the parameters describing the compliant coating on the interaction between the fluid and the cylindrical compliant coating are shown throughout the numerical results. It is shown that by increasing the compliancy of the coating, the bubble life time is decreased and the mass per unit area has an important role in bubble behavior.

The Influence of Acoustic Cavitation to Microscopic Material Removal in Polishing Process Based on Vibration of Liquid: A Numerical Study

2006 ◽  
Vol 532-533 ◽  
pp. 301-304 ◽  
Author(s):  
Zhong Ning Guo ◽  
Zhi Gang Huang ◽  
Xin Chen
Keyword(s):  
Material Removal ◽  
High Speed ◽  
Bubble Dynamics ◽  
Numerical Study ◽  
Dissipative Particle Dynamics ◽  
Thermal Conditions ◽  
Acoustic Cavitation ◽  
Ultrasonic Frequency ◽  
Polishing Process ◽  
Cavitation Phenomenon

In Polishing Process based on Vibration of Liquid (PVL), abrasive particles driven by polishing liquid will brush and etch workpiece to achieve material removal. Because the liquid is vibrated in ultrasonic frequency, polishing process will be greatly affected by cavitation phenomenon. The critical thermal conditions and high-speed liquid jet produced by bubble dynamics may damage workpiece. A refined Dissipative Particle Dynamics method is applied to study the effect of acoustic cavitation on PVL. Validity of the numerical simulation is tested according to experimental results.

The Pressure Field Radiated by Cavitation Bubble in the Grinding Area of Power Ultrasonic Honing

2014 ◽  
Vol 1027 ◽  
pp. 44-47 ◽  
Author(s):  
Xi Jing Zhu ◽  
Ce Guo ◽  
Jian Qing Wang
Keyword(s):  
Radiation Pressure ◽  
Cavitation Bubble ◽  
Bubble Dynamics ◽  
Pressure Field ◽  
Bubble Radius ◽  
Ultrasonic Frequency ◽  
Power Ultrasonic ◽  
Cutting Chatter ◽  
Grinding Mechanism ◽  
Order Of Magnitude

The pressure field induced by cavitaion bubble is responsible for the grinding mechanism and the cutting chatter of power ultrasonic honing. Based on the cavitation bubble dynamics model in the grinding area of power ultrasonic honing, the radiation pressure field of cavitation bubble was established. Experimental results show that the bubble is distributed in the grinding area like honeycomb and the size is about 10μm. Numerical simulation of dynamics and pressure field of cavitation bubble was performed. Numerical results show the dynamic behavior of cavitation bubble presents grow, expend and collapse under an acoustic cycle. However the expansion amplitude of bubble can be decreased and the collapse time can be extended and even collapse after several acoustic cycles with increasing ambient bubble radius. The bubble radiation pressure during collapsing bubble increases with increasing ultrasonic amplitude and ultrasonic frequency. And the pressure value of collapsing bubble is about 10Mpa which is more an order of magnitude than atmospheric pressure.

scholarly journals The collapse of a cavitation bubble in shear flows—A numerical study

1995 ◽  
Vol 7 (11) ◽  
pp. 2608-2616 ◽  
Author(s):  
Po‐Wen Yu ◽  
Steven L. Ceccio ◽  
Grétar Tryggvason
Keyword(s):  
Cavitation Bubble ◽  
Shear Flows ◽  
Numerical Study

Cavitation Bubble Dynamics Induced by Hydrodynamic Pressure Oil Film in Ultrasonic Vibration Honing

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Ce Guo ◽  
XiJing Zhu ◽  
Jia Liu ◽  
Dan Zhang
Keyword(s):  
Ultrasonic Vibration ◽  
Cavitation Bubble ◽  
Bubble Dynamics ◽  
Prediction Method ◽  
Hydrodynamic Pressure ◽  
Ultrasonic Frequency ◽  
Film Pressure ◽  
Oil Film ◽  
Cavitation Effect ◽  
Oil Film Pressure

During ultrasonic vibration honing (UVH), a thin hydrodynamic oil film formed can seriously affect the cavitation effect in the grinding fluid, but the mechanism is still unclear now. Based on the hydrodynamics theory, a revised cavitation bubble model with oil film pressure is developed, and it has been calculated by the four-order Runge–Kutta method. The calculation results show that the oil film pressure under UVH is a positive–negative alternant pulse pressure, and it can induce the secondary expansion of the bubble, leading to double microjets during the process of the bubble collapsing. The effects of ultrasonic amplitude, ultrasonic frequency, oil film height, and reciprocation speed of the honing stone on the bubble dynamics are discussed. With the increase of ultrasonic amplitude, the amplitude of the bubble expansion is increased, and the oscillation interval is extended. As increasing normalized oil film height, the variation of the bubble first expansion is slight, while the amplitude of the bubble secondary expansion is reduced and the oscillation interval is also shortened. The main effect of ultrasonic frequency and reciprocation speed of the honing stone on the bubble dynamics is connected with the secondary bubble expansion. The bubble secondary expansion is decreased with the increasing reciprocation speed of the honing stone, ultrasonic frequency, and oil film height. The results of the simulations are consistent with the surface roughness measurements well, which provides a theoretical prediction method of cavitation bubbles control.

Numerical Study of Gas and Cavitation Bubble Dynamics in Liquid Mercury Under Negative Pressure

2007 ◽  
Author(s):  
Masato Ida ◽  
Takashi Naoe ◽  
Masatoshi Futakawa
Keyword(s):  
Cavitation Bubble ◽  
Bubble Dynamics ◽  
Numerical Study ◽  
Gas Bubbles ◽  
Proton Accelerator ◽  
Positive Pressure ◽  
Nuclear Facilities ◽  
Cavitation Inception ◽  
Liquid Mercury ◽  
Numerical Studies

Gas and cavitation bubble dynamics have been studied numerically to evaluate the effect of gas bubble injection on the suppression of cavitation inception. In our previous studies it has been demonstrated by direct observation that cavitation occurs in liquid mercury when mechanical impacts are imposed and it must seriously shorten the lifetime of nuclear facilities using liquid mercury, such as the mercury spallation target of the J-PARC (Japan Proton Accelerator Research Complex). In this paper, using single-bubble and multibubble models we have performed numerical studies on the dynamics of cavitation bubbles in liquid mercury with and without preexisting gas bubbles, and have clarified that if the mercury involves gas bubbles much larger than the cavitation nuclei, cavitation inception is effectively suppressed due to the positive pressure radiated by the gas bubbles. Our recent experimental results (not shown in the present paper) have confirmed the effectiveness of the bubble injection.

scholarly journals Multibubble Sonoluminescence from a Theoretical Perspective

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4624
Author(s):  
Kyuichi Yasui
Keyword(s):  
Cavitation Bubble ◽  
Theoretical Perspective ◽  
Line Emission ◽  
Bubble Collapse ◽  
Ultrasonic Frequency ◽  
Liquid Droplets ◽  
Noncondensable Gases ◽  
Weakly Ionized ◽  
Bubble Interaction ◽  
Surrounding Liquid

In the present review, complexity in multibubble sonoluminescence (MBSL) is discussed. At relatively low ultrasonic frequency, a cavitation bubble is filled mostly with water vapor at relatively high acoustic amplitude which results in OH-line emission by chemiluminescence as well as emissions from weakly ionized plasma formed inside a bubble at the end of the violent bubble collapse. At relatively high ultrasonic frequency or at relatively low acoustic amplitude at relatively low ultrasonic frequency, a cavitation bubble is mostly filled with noncondensable gases such as air or argon at the end of the bubble collapse, which results in relatively high bubble temperature and light emissions from plasma formed inside a bubble. Ionization potential lowering for atoms and molecules occurs due to the extremely high density inside a bubble at the end of the violent bubble collapse, which is one of the main reasons for the plasma formation inside a bubble in addition to the high bubble temperature due to quasi-adiabatic compression of a bubble, where “quasi” means that appreciable thermal conduction takes place between the heated interior of a bubble and the surrounding liquid. Due to bubble–bubble interaction, liquid droplets enter bubbles at the bubble collapse, which results in sodium-line emission.

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