scholarly journals A study on thermally controlled bubble growth in a superheated liquid with a thermal non-equilibrium cavitation model based on energy balances on a fixed fluid mass

2015 ◽  
Author(s):  
M. Nickaeen ◽  
T. Jaskolka ◽  
S. Mottyll ◽  
R. Skoda
Keyword(s):  
Bubble Growth ◽  
Superheated Liquid ◽  
Cavitation Model ◽  
Fluid Mass ◽  
Model Based ◽  
Energy Balances ◽  
Non Equilibrium

scholarly journals A new cavitation model based on bubble-bubble interactions

2018 ◽  
Vol 30 (12) ◽  
pp. 123301 ◽  
Author(s):  
M. Adama Maiga ◽  
O. Coutier-Delgosha ◽  
D. Buisine
Keyword(s):  
Cavitation Model ◽  
Bubble Interactions ◽  
Model Based

Collective Effects on the Growth of Vapor Bubbles in a Superheated Liquid

1984 ◽  
Vol 106 (4) ◽  
pp. 486-490 ◽  
Author(s):  
G. L. Chahine ◽  
H. L. Liu
Keyword(s):  
Collective Behavior ◽  
Bubble Growth ◽  
Theoretical Study ◽  
Pressure Field ◽  
Bubble Radius ◽  
Significant Inhibition ◽  
Collective Effects ◽  
Superheated Liquid ◽  
Vapor Bubbles ◽  
Bubble Interaction

The problem of the growth of a spherical isolated bubble in a superheated liquid has been extensively studied. However, very little work has been done for the case of a cloud of bubbles. The collective behavior of the bubbles departs considerably from that of a single isolated bubble, due to the cumulative modification of the pressure field from all other bubbles. This paper presents a theoretical study on bubble interaction in a superheated liquid during the growth stage. The solution is sought in terms of matched asymptotic expansions in powers of ε, the ratio between rb0, a characteristic bubble radius and l0, the interbubble distance. Numerical results show a significant inhibition of the bubble growth rate due to the presence of interacting bubbles. In addition, the temperature at the bubble wall decreases at a slower rate. Consequently, the overall heat exchange during the bubble growth is reduced.

Simulation of cavitation in outward-opening piezo-type pintle injector nozzles

2008 ◽  
Vol 222 (10) ◽  
pp. 1895-1910 ◽  
Author(s):  
E Giannadakis ◽  
D Papoulias ◽  
A Theodorakakos ◽  
M Gavaises
Keyword(s):  
Bubble Growth ◽  
Large Scale ◽  
Direct Injection ◽  
Bubble Formation ◽  
Needle Valve ◽  
Transient Effects ◽  
Cavitation Model ◽  
Gasoline Engines ◽  
Opening And Closing ◽  
Vapour Film

The onset and development of cavitation in the annular needle seat passage of piezo-driven outward-opening pintle injector nozzles used with spray-guided direct-injection gasoline engines are studied using a Eulerian-Lagrangian computational fluid dynamics cavitation model. Cavitation is formed because of the fluid acceleration taking place at the needle sealing area and it has been found to be affected by its geometric details. Various submodels for nucleation and bubble formation, further bubble growth and collapse, as well as bubble break-up and transport are incorporated into the model. Qualitative model validation is performed against experimental data reported elsewhere in large-scale nozzle replicas, showing similar cavitation patterns to be formed. These consist of vapour pockets rather than a continuous vapour film and develop transiently in a rather chaotic manner around the circumferential needle sealing area, even under stationary geometry and fixed-flowrate conditions. Further transient effects associated with the fast opening and closing of the piezo-controlled needle valve are also presented.

Numerical Solution of Thermal and Fluid Flow With Phase Change by VOF Method

2000 ◽  
Author(s):  
Hidemi Shirakawa ◽  
Yasuyuki Takata ◽  
Takehiro Ito ◽  
Shinobu Satonaka
Keyword(s):  
Fluid Flow ◽  
Free Surface ◽  
Phase Change ◽  
Calculation Result ◽  
Bubble Growth ◽  
Present Method ◽  
Spherical Shape ◽  
Superheated Liquid ◽  
One Dimensional ◽  
Solidification Problem

Abstract Numerical method for thermal and fluid flow with free surface and phase change has been developed. The calculation result of one-dimensional solidification problem agrees with Neumann’s theoretical value. We applied it to a bubble growth in superheated liquid and obtained the result that a bubble grows with spherical shape. The present method can be applicable to various phase change problems.

A New Cavitation Model Based on Evaporation and Condensation Theory

2009 ◽  
Author(s):  
Gang Chen ◽  
Shuhong Liu ◽  
Guangjun Cao ◽  
Yulin Wu ◽  
Suhong Fu ◽  
...  
Keyword(s):  
Surface Tension ◽  
Aerodynamic Drag ◽  
Water Pressure ◽  
Bubble Diameter ◽  
Simulation Models ◽  
Cavitation Model ◽  
Local Pressure ◽  
Two Phase ◽  
Evaporation And Condensation ◽  
Model Based

Cavitation is a phenomenon which occurs where the local pressure falls off under the vapor pressure. Over the past few years, numerical simulation models for cavitation have been developed significantly in order to investigate the mechanism of cavitation. In the paper, A local homogeneous cavitation model based on the theory of evaporation and condensation has been deduced, which is used to describe the phase change between water and vapor. The RNG k–ε turbulence model is used to simulate the turbulent flow and the finite volume method is employed to discrete the governing equations. The effects of surface tension of water, pressure fluctuations and non-condensable gases are included in the mass transfer cavitation model. Also in order to neglect the effects of the quantities such as the bubble number and bubble diameter, which is difficult to measure, the relations between the aerodynamic drag and surface tension forces is used to describe the bubble diameter. In order to evaluate the new cavitation model, the two phase cavitation flows around a NACA0015 hydrofoil at different attack angle and different cavitation number are simulated by the new cavitation model, and compared with references, which showed good agreement with the experiments.

Inertial-thermal governed vapor bubble growth in highly superheated liquid

2005 ◽  
Vol 41 (10) ◽  
pp. 855-863 ◽  
Author(s):  
Alexandr A. Avdeev ◽  
Yuri B. Zudin
Keyword(s):  
Vapor Bubble ◽  
Bubble Growth ◽  
Superheated Liquid
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