On the Mechanics of Vapor Bubble Collapse

1965 ◽  
Vol 87 (2) ◽  
pp. 209-220 ◽  
Author(s):  
L. W. Florschuetz ◽  
B. T. Chao
Keyword(s):  
Heat Transfer ◽  
Vapor Bubble ◽  
Atmospheric Pressure ◽  
Dimensionless Parameter ◽  
Free Fall ◽  
Step Change ◽  
Bubble Collapse ◽  
Relative Importance ◽  
Vapor Bubbles ◽  
Collapse Rate

The mechanics of vapor bubble collapse under spherically symmetrical conditions is examined to ascertain the relative importance of the effects of liquid inertia and heat transfer on the collapse rate. A dimensionless parameter, Beff, is identified to characterize the mode of collapse. Discriminating values of this parameter are suggested for the simple case where the collapse is initiated by a step change in pressure or temperature. For heat transfer controlled collapse, a model is also proposed to account for the influence of a permanent gas present in the bubble. Experimental results for bubbles with initial radii ranging from 0.3 cm to 0.9 cm collapsing in water and ethyl alcohol at atmospheric pressure levels and under free fall conditions are presented. The pressure difference ranges from 12 cm Hg to 63 cm Hg and the corresponding degrees of subcooling are 5 deg C to 45 deg C. Data are also given for water vapor bubbles containing significant amounts of nitrogen, helium, and xenon. When compared with theory, reasonable agreements are obtained. For slowly collapsing bubbles, the significance of small translational velocities is brought to attention. Photographic evidences are also given for bubble instability under suitable conditions.

Heat Transfer Controlled Collapse of a Cylindrical Vapor Bubble in a Vertical Isothermal Tube

1977 ◽  
Vol 99 (3) ◽  
pp. 392-397 ◽  
Author(s):  
D. R. Pitts ◽  
H. C. Hewitt ◽  
B. R. McCullough
Keyword(s):  
Heat Transfer ◽  
Vapor Bubble ◽  
High Speed ◽  
Experimental Results ◽  
Heat Transfer Analysis ◽  
Experimental Program ◽  
Bubble Collapse ◽  
Electric Heater ◽  
Vapor Bubbles ◽  
Experimental Apparatus

An experimental program was conducted to determine the collapse rate of slug-type vapor bubbles rising due to buoyancy through subcooled parent liquid in a vertical isothermal tube. The experimental apparatus included a vertical glass tube with an outer glass container providing a constant temperature water bath for the inner tube. The inner tube contained distilled, deaerated water, and water vapor bubbles were generated at the bottom of this tube with a pulsed electric heater. The parent liquid was uniformly subcooled with respect to the vapor bubble resulting in heat transfer controlled bubble collapse. Collapse rates and rise velocities were recorded by high-speed motion picture photography. Over a limited range of subcooling, the bubble collapse was well behaved, and a simple, quasi-steady boundary layer heat transfer analysis adapted from slug flow over a flat plate correlated the experimental results with a high degree of accuracy. Experimental results were obtained with tubes having inside diameters of 0.0127, 0.0218, and 0.0381 m and for a range of subcooling from 0.5 to 9.0 K.

Correlation Between Behaviors of the Vapor Bubbles and the Characteristics of the Heat Transfer Over the Heated Surface on MEB

2013 ◽  
Author(s):  
Takahito Saiki ◽  
Tomohiko Osawa ◽  
Ichiro Ueno ◽  
Chungpyo Hong
Keyword(s):  
Heat Transfer ◽  
Vapor Bubble ◽  
High Speed ◽  
Heated Surface ◽  
High Heat ◽  
Frame Rate ◽  
High Heat Flux ◽  
Heated Plate ◽  
Thin Wire ◽  
Vapor Bubbles

A series of experiments on subcooled pool boiling on a plate and on a thin wire are carried out. We focus on the condensation and collapse processes of vapor bubbles generated on the heated surface. We find the different patterns of the vapor bubble behaviors resulting in the emission of the microbubbles around the heated plate and the thin wire by employing high-speed observation with frame rate up to 150,000 frame per second (fps). From the experimental results, we provide a physical explanation on the correlation between the behavior of the vapor bubble at a high heat flux and the heat transfer characteristics. We propose this simple core-periphery model as a qualitative model for understanding the generation of the MEB.

Numerical Simulation of Vapor–Bubble Collapse—Heat Transfer and Nonlinear Dynamics Issues

2020 ◽  
Vol 142 (3) ◽  
Author(s):  
Jyoti Bhati ◽  
Swapan Paruya ◽  
Subhramaniam Pushpavanam
Keyword(s):  
Heat Transfer ◽  
Nonlinear Dynamics ◽  
Steady State ◽  
Vapor Bubble ◽  
Bubble Radius ◽  
Bubble Collapse ◽  
Large Contribution ◽  
Steady State Analysis ◽  
The Stability ◽  
State Analysis

Abstract In this work, we compute the dynamics of a spherical vapor-bubble in an infinite pool of subcooled water during bubble collapse using our semi-analytical method. The main contribution of this work is to bring out the dynamics of nonmonotonic bubble collapse describing heat transfer characteristics and nonlinear dynamics. The dynamics shows the variation of radius with time for collapsing vapor bubble at different subcooling ΔTsub of 1.40 K to 35 K. The present approach accurately determines the bubble radius decreasing with time and has been compared with our experimental results, the experiment from literature, the other theories, and correlations. As it is noted that the literature lacks steady-state analysis of oscillating bubble collapse, we also report the steady-state analysis and the bifurcation analysis of bubble collapse at a pressure of 1.0 atm to check the stability of bubble collapse. The effect of ΔTsub and initial bubble radius R0 on dynamics of bubble collapse has been analyzed. The collapse of big bubbles involves with the bubble oscillations because of a large contribution of liquid inertia and the collapse of very small bubbles essentially occurs in heat transfer regime.

scholarly journals The Single-Blow Problem Including the Effects of Longitudinal Conduction

1964 ◽  
Author(s):  
C. P. Howard
Keyword(s):  
Heat Transfer ◽  
Porous Media ◽  
Heat Conduction ◽  
Transient Behavior ◽  
Step Change ◽  
Graphical Form ◽  
Compact Heat Exchanger ◽  
Fluid Temperature ◽  
Transfer Data ◽  
Method Of Calculation

The results are presented from a numerical finite-difference method of calculation for the transient behavior of porous media when subjected to a step change in fluid temperature considering the case where the longitudinal thermal heat conduction cannot be neglected. These results, given in tabular and graphical form, provide a useful means for evaluating the heat-transfer data obtained from the transient testing of compact heat-exchanger surfaces.

Evaporation of Single Drops of n-Pentane/n-Hexane Mixtures in Water

1992 ◽  
Vol 114 (4) ◽  
pp. 965-971 ◽  
Author(s):  
H. Shimaoka ◽  
Y. H. Mori
Keyword(s):  
Heat Transfer ◽  
Temperature Difference ◽  
Vapor Bubble ◽  
Experimental Results ◽  
Rise Velocity ◽  
Heat Transfer Characteristics ◽  
Two Phase ◽  
Transfer Characteristics ◽  
Preceding Work ◽  
Liquid Vapor

The evaporation of isolated drops (2.1−3.0 mm diameter) of nonazeotropic n-pentane/n-hexane mixtures in the medium of water was observed under pressures of 0.11−0.46 MPa and temperature differences up to 27 K. The mole fractions of n-pentane, x, in the mixtures were set at 0.9, 0.5, 0.1, and 0, to be completed by the condition x = 1 set in a preceding work (Shimaoka and Mori, 1990). Experimental results are presented in terms of the instantaneous rise velocity of, and an expression of instantaneous heat transfer to, each drop evaporating and thereby transforming into a liquid/vapor two-phase bubble and finally into a vapor bubble. The dependencies of the heat transfer characteristics on the pressure, the temperature difference, and x are discussed.

The Origin of the Dynamic Growth of Vapor Bubbles Related to Vapor Explosions

1998 ◽  
Vol 120 (1) ◽  
pp. 174-182 ◽  
Author(s):  
H. S. Lee ◽  
H. Merte
Keyword(s):  
Heat Transfer ◽  
Bubble Growth ◽  
Hydrodynamic Instability ◽  
Early Growth ◽  
Instability Mechanism ◽  
Vapor Bubbles ◽  
Vapor Interface ◽  
Vapor Explosions ◽  
Dynamic Growth ◽  
Classical Hydrodynamic

An explosive type of vapor bubble growth was observed during pool boiling experiments in microgravity using R-113. Photographs reveal that the liquid-vapor interface of the explosive bubbles are wrinkled and corrugated, leading to the conclusion that some type of instability mechanism is acting. The classical hydrodynamic instability theories of Landau and Rayleigh-Taylor do not consider the effect of heat transfer, at the interface, which is believed to be responsible for the observed instability of the evaporating surface. This was confirmed by the mechanisms proposed by Prosperetti and Plesset, combined with a model of the early growth of spherical vapor bubbles.

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