Influence of Homogeneous Condensation Inside a Small Gas Bubble on Its Pressure Response

1985 ◽  
Vol 107 (2) ◽  
pp. 281-286 ◽  
Author(s):  
Y. Matsumoto ◽  
A. E. Beylich
Keyword(s):  
Critical Pressure ◽  
Ambient Pressure ◽  
Bubble Radius ◽  
Gas Bubble ◽  
Pressure Reduction ◽  
Latent Heat Release ◽  
Liquid Temperature ◽  
Cavitation Inception ◽  
Mist Formation ◽  
Surrounding Liquid

The response of a small gas bubble to an ambient pressure reduction is investigated theoretically. Numerical results show that the temperature inside the bubble decreases due to adiabatic expansion at the first stage, then it recovers almost to the surrounding liquid temperature because of latent heat release caused by mist formation inside the bubble. Consequently, the bubble behaves apparently isothermally. The relation between the initial bubble radius and the critical pressure for cavitation inception to stepwise ambient pressure reduction becomes close to the relation under the assumption of isothermal change in the gas mixture inside the bubble.

scholarly journals HIGH PRESSURE TRANSPORT STUDY OF NON-FERMI LIQUID BEHAVIOUR IN U2Pt2In AND U3Ni3Sn4

2002 ◽  
Vol 16 (20n22) ◽  
pp. 2998-3003 ◽  
Author(s):  
A. DE VISSER ◽  
P. ESTRELA ◽  
T. NAKA
Keyword(s):  
High Pressure ◽  
Electrical Resistivity ◽  
Fermi Liquid ◽  
Critical Pressure ◽  
Ambient Pressure ◽  
Strongly Correlated ◽  
Liquid Temperature ◽  
Resistivity Measurements ◽  
Pressure Transport ◽  
The Stability

The strongly correlated metals U 2 Pt 2 In and U 3 Ni 3 Sn 4 show pronounced non-Fermi liquid (NFL) phenomena at ambient pressure. Here we review single-crystal electrical resistivity measurements under pressure (p ≤ 1.8 GPa) conducted to investigate the stability of the NFL phase. For tetragonal U 2 Pt 2 In (I ‖ a) we observe a rapid recovery of the Fermi-liquid T2-term with pressure. The Fermi-liquid temperature varies as T FL ~ p-p c , where p c =0 is a critical pressure. The analysis within the magnetotransport theory of Rosch provides evidence for the location of U 2 Pt 2 In at a p=0 antiferromagnetic critical point (QCP). In the case of cubic U 3 Ni 3 Sn 4 we find T FL ~ (p-p c )1/2. The analysis provides evidence for an antiferromagnetic QCP in U 3 Ni 3 Sn 4 at a negative pressure p c = -0.04±0.04 GPa

Contribution of Homogeneous Condensation Inside Cavitation Nuclei to Cavitation Inception

1986 ◽  
Vol 108 (4) ◽  
pp. 433-437
Author(s):  
Y. Matsumoto
Keyword(s):  
Ambient Pressure ◽  
Pressure Change ◽  
Numerical Results ◽  
Resolving Power ◽  
Scattering Method ◽  
Cavitation Inception ◽  
Homogeneous Condensation ◽  
Cavitation Nuclei ◽  
Surrounding Liquid ◽  
Good Agreement

The response of a small gas bubble, so-called cavitation nucleus, to the reduction of ambient pressure is investigated theoretically and experimentally. Numerical results show that the gas mixture inside the bubble expands adiabatically and the temperature of the mixture decreases rapidly at the first stage, however the temperature recovers soon to the surrounding liquid temperature by homogeneous condensation which forms a mist inside the bubble. Consequently, the bubble grows almost isothermally. Experiments have been performed using a hydro-shock tube. The radius of a small bubble has been measured by a light-scattering method whose time resolving power is one micro-second. The experimental results are found to be in good agreement with the numerical results calculated using the ambient pressure change measured in the test section.

Reconsideration of Cavitation Inception Theory

2007 ◽  
Author(s):  
Takeru Yano ◽  
Shigeo Fujikawa ◽  
Tao Yu
Keyword(s):  
Phase Plane ◽  
Critical Radius ◽  
Ambient Pressure ◽  
Bubble Radius ◽  
Inviscid Limit ◽  
Saddle Node Bifurcation ◽  
Cavitation Inception ◽  
Saddle Node ◽  
Pass Through ◽  
New Criterion

The nonlinear dynamics of a spherical gas bubble in a liquid water is reconsidered on the basis of the Rayleigh-Plesset equation with particularly emphasis on the unstable behavior with respect to infinitesimal perturbations. The evolution of bubble radius after the discontinuous change of ambient pressure is theoretically analyzed, and the classical critical pressure and critical radius are re-derived as a saddle-node bifurcation point, when the center and saddle on the phase plane merge into a degenerate unstable singular point in the phase plane. Before the saddle-node bifurcation, there is a separatrix issuing from and entering into the saddle point in the inviscid limit. We propose a new criterion for cavitation inception: the ambient pressure that makes the separatrix pass through the initial bubble radius. This criterion gives a cavitation inception pressure higher than the classical one. The effects of viscosity and thermal conductivity are also discussed.

scholarly journals GROWTH OF A GAS BUBBLE IN A STEADY DIFFUSION FIELD IN A TISSUE UNDERGOING DECOMPRESSION

2016 ◽  
Vol 21 (6) ◽  
pp. 762-773 ◽  
Author(s):  
Selim A. Mohammadein ◽  
Khaled G. Mohamed
Keyword(s):  
Surface Tension ◽  
Ambient Pressure ◽  
Bubble Radius ◽  
Density Ratio ◽  
Diffusion Field ◽  
Gas Bubble ◽  
Concentration Difference ◽  
Initial Concentration ◽  
Average Temperature ◽  
Dominant Parameter

This paper presents parameterized study on the growth of a convective gas bubble in tissues of a steady diffusion field. Resulting formulae are obtained analytically, which are valid for constant ambient pressure. It’s found that the growing bubble radius is proportional to initial bubble radius, initial concentration difference, diver’s average temperature and initial void fraction which is the dominant parameter, while it’s inversely proportional to surface tension, viscosity, density ratio and ambient pressure. Comparison to some previous work is performed.

Behavior of Inert Gas Bubbles in Forced Convective Liquid Metal Circuits

1976 ◽  
Vol 98 (1) ◽  
pp. 5-11 ◽  
Author(s):  
W. J. Minkowycz ◽  
D. M. France ◽  
R. M. Singer
Keyword(s):  
Liquid Metal ◽  
Bubble Dynamics ◽  
Bubble Radius ◽  
Gas Bubbles ◽  
Inert Gas ◽  
Liquid Sodium ◽  
Gas Bubble ◽  
Flowing Liquid ◽  
Argon Gas ◽  
The Core

Conservation equations are derived for the motion of a small inert gas bubble in a large flowing liquid-gas solution subjected to large thermal gradients. Terms which are of the second order of magnitude under less severe and steady-state conditions are retained, thus resulting in an expanded form of the Rayleigh equation. The bubble dynamics is a function of opposing mechanisms tending to increase or decrease bubble volume while being transported with the solution. Diffusion of inert gas between the bubble and the solution is one of the most important of these mechanisms included in the analysis. The analytical model is applied to an argon gas bubble flowing in a weak solution of argon gas in liquid sodium. Calculations are performed for these fluids under conditions typical of normal and abnormal operation of a liquid metal fast breeder reactor (LMFBR) core and the resulting bubble radius, internal gas pressure, and mass of inert gas are presented in each case. An important result obtained indicates that inert gas bubbles reaching the core inlet of an LMFBR will always grow as they traverse the core under normal and extreme abnormal conditions and that the rate of growth is quite small in all cases.

The influence of surface adsorption on microbubble dynamics

2008 ◽  
Vol 366 (1873) ◽  
pp. 2103-2115 ◽  
Author(s):  
E Stride
Keyword(s):  
Dynamic Behaviour ◽  
Ambient Pressure ◽  
Surface Coatings ◽  
Pure Liquid ◽  
High Frequencies ◽  
Wide Range ◽  
Recent Developments ◽  
Tension And Compression ◽  
Cavitation Detection ◽  
Surrounding Liquid

In a pure liquid, the behaviour of a gas or vapour microbubble is determined primarily by its size, the ambient pressure and the properties of the surrounding liquid. In practice, however, adsorption of a dissolved substance from the surrounding liquid onto the microbubble surface will often take place, producing a thin coating which can significantly affect both the microbubble's stability and its dynamic response. This can have important implications in a wide range of applications, including underwater acoustics, cavitation detection, medical imaging and drug delivery. The aim of this paper is to review the existing theoretical treatments of coated microbubbles and to present and discuss some recent developments. It will be shown that the presence of the coating can substantially modify the amplitude of microbubble volumetric oscillation, resonance characteristics and relative amplitude in tension and compression. Finally, the need for improved understanding of the dynamic behaviour of surface coatings at high frequencies will be discussed.

On the theory of air‐gun bubble interactions

Geophysics ◽  
1988 ◽  
Vol 53 (2) ◽  
pp. 192-200 ◽  
Author(s):  
R. C. Bailey ◽  
P. B. Garces
Keyword(s):  
Ambient Pressure ◽  
Bubble Radius ◽  
Dynamical Equations ◽  
Local Pressure ◽  
Know How ◽  
R And D ◽  
Bubble Interactions ◽  
Interaction Terms ◽  
Air Gun ◽  
Marine Air

Calculation of the seismic signatures of marine air‐gun arrays often requires that the interactions among the bubbles from air guns be taken into account. The standard method of doing this is to use the Giles‐Johnston approximation in which a time‐dependent effective ambient pressure is calculated for each bubble as the sum of the true ambient pressure and the local pressure signals of all the other bubbles in the array. These effects of interaction have a relative importance in the dynamics proportional to (R/D), where R and D are the typical bubble radius and interbubble separation, respectively. To ensure that current methods of calculating signatures are accurate, it is necessary to know how good this approximation is. This paper shows that there are no interaction terms in the full dynamical equations proportional to [Formula: see text] or [Formula: see text], and that the errors of the Giles‐Johnston approximation are only of order [Formula: see text]. The Giles‐Johnston approximation is therefore justified even for fairly accurate signature calculations for noncoalescing bubbles. The analysis here also shows how to incorporate bubble motions and deformations into the dynamical equations, so that the errors can be reduced to order [Formula: see text] if desired.

Choice of Bubble Radius in Floatation Refining of Magnesium Alloy

2009 ◽  
Vol 610-613 ◽  
pp. 775-779
Author(s):  
Zhong Hua Su ◽  
Wei Dong Xie ◽  
Xiao Dong Peng ◽  
Yan Yang ◽  
Qun Yi Wei
Keyword(s):  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Bubble Radius ◽  
Dynamics Analysis ◽  
Gas Bubble ◽  
Process Scheme ◽  
Refining Method ◽  
Relationship Of ◽  
Impurity Models ◽  
Choice Method

The species and shapes of impurities in magnesium alloy melt were studied. Floatation Refining method of Magnesium Alloys melt and eduction dynamics analysis were used to judge the floatation condition of gas bubble with MgO impurity. Models of floatation eduction were established to study the dynamics relationship of weight, drag and buoyancy. The relation curve between refining gas bubble radius and floating up rate was established. The choice method of gas bubble radius was provided and a practical process scheme proposed for floatation refining of magnesium alloys melt.

Subcritical and Supercritical Nanodroplet Evaporation: A Molecular Dynamics Investigation

2007 ◽  
Author(s):  
S. Mikkilineni ◽  
E. S. Landry ◽  
A. J. H. McGaughey
Keyword(s):  
Molecular Dynamics ◽  
Critical Temperature ◽  
Critical Pressure ◽  
Ambient Pressure ◽  
Transition Line ◽  
Ambient Temperatures ◽  
Lennard Jones ◽  
Temperature And Pressure ◽  
A New Technique ◽  
Dynamics Simulations

Molecular dynamics simulations are used to investigate the subcritical and supercritical evaporation of a Lennard-Jones (LJ) argon nanodroplet in its own vapor. Using a new technique to control both the ambient temperature and pressure, a range of conditions are considered to define a transition line between subcritical and supercritical evaporation. The evaporation is considered to be supercritical if the surface temperature of the droplet reaches the LJ argon critical temperature during its lifetime. Between ambient temperatures of 300 K and 800 K, the transition from subcritical to supercritical evaporation is observed to occur at an ambient pressure 1.4 times greater than the LJ argon critical pressure. For subcritical conditions, the droplet lifetimes obtained from the simulations are compared to independently predicted lifetimes from the D2 law.

Analytical Investigation on the Homogeneous Nucleation in a Mono-Component and Bi-Component Droplet

2019 ◽  
Author(s):  
Xi Xi ◽  
Hong Liu ◽  
Chang Cai ◽  
Ming Jia ◽  
Weilong Zhang
Keyword(s):  
Nucleation Rate ◽  
Homogeneous Nucleation ◽  
Ambient Pressure ◽  
Analytical Investigation ◽  
Bubble Nucleation ◽  
Nucleation Theory ◽  
Classical Nucleation Theory ◽  
Liquid Temperature ◽  
Wide Range ◽  
Good Agreement

Abstract The work attempts to analyze the performance of homogeneous nucleation by using the non-equilibrium thermodynamics theory and the classical nucleation theory. A nucleation rate graph was constructed under a wide range of operating temperature conditions. The results indicate that the superheat limit temperature (SLT) estimated by the modified homogeneous nucleation sub-model is in good agreement with the experimental results. The nucleation rate increases exponentially with the liquid temperature rise when the liquid temperature exceeds the SLT under atmospheric pressure. The superheated temperature needed to trigger the bubble nucleation decreases with the elevated ambient pressure.

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