A Simplified Model for Predicting Vapor Bubble Growth Rates in Heterogeneous Boiling

1995 ◽  
Vol 117 (4) ◽  
pp. 976-980 ◽  
Author(s):  
W. C. Chen ◽  
J. F. Klausner ◽  
R. Mei
Keyword(s):  
Experimental Data ◽  
Growth Rate ◽  
Vapor Bubble ◽  
Bubble Growth ◽  
Heating Surface ◽  
Simplified Model ◽  
Order Ordinary Differential Equation ◽  
Empirical Parameter ◽  
Wetting Fluids ◽  
Microlayer Evaporation

A simplified model, based on heat transfer through a wedge-shaped liquid microlayer and a lumped thermal analysis for a solid heater, is developed for predicting the vapor bubble growth rate in heterogeneous pool boiling. A first-order ordinary differential equation is obtained for the bubble growth rate. An empirical parameter, C2, which characterizes the region of the heating surface influenced by microlayer evaporation, is determined by matching the existing experimental data with the predicted growth rate. The present bubble growth model compares well with the available experimental data for intermediate and moderately wetting fluids in which Jacob number ranges from 0.52 to 1974.

A New Method for Estimating Bubble Diameter At Different Gravity Levels for Nucleate Pool Boiling

2021 ◽  
Author(s):  
Sandipan Banerjee ◽  
Yongsheng Lian ◽  
Yang Liu ◽  
Mark Sussman
Keyword(s):  
Heat Transfer ◽  
Growth Rate ◽  
Vapor Bubble ◽  
Bubble Growth ◽  
Bubble Diameter ◽  
Nucleate Boiling ◽  
New Method ◽  
Space Applications ◽  
Earth Gravity ◽  
Micro Gravity

Abstract Nucleate boiling has significant applications in earth gravity( in industrial cooling applications) and micro-gravity conditions (in space exploration, specifically in making space applications more compact). However, the effect of gravity on the growth rate and bubble size is not yet well understood. We perform numerical simulations of nucleate boiling using an adaptive Moment-of-Fluid (MoF) method for a single vapor bubble (water or Perfluoro-n-hexane) in saturated liquid for different gravity levels. Results concerning the growth rate of the bubble, specifically the departure diameter and departure time have been provided. The MoF method has been first validated by comparing results with a theoretical solution of vapor bubble growth in super-heated liquid without any heat-transfer from the wall. Next, bubble growth rate, bubble shape and heat transfer results under earth gravity, reduced gravity and micro-gravity conditions are reported and they are in good agreement with experiments. Finally, a new method is proposed for estimating the bubble diameter at different gravity levels. This method is based on an analysis of empirical data at different gravity values and using power-series curve fitting to obtain a generalized bubble growth curve irrespective of the gravity value. This method is shown to provide a good estimate of the bubble diameter for a specific gravity value and time.

The Instability of Vapor Bubble Growth within the Diesel Droplet under the Condition of Supercavitation

2012 ◽  
Vol 512-515 ◽  
pp. 477-480 ◽  
Author(s):  
Ming Lv ◽  
Zhi Ning ◽  
Kai Yan
Keyword(s):  
Growth Rate ◽  
Reynolds Number ◽  
Vapor Bubble ◽  
Bubble Growth ◽  
Volume Fraction ◽  
Ambient Air ◽  
Analytical Form ◽  
Paper Analysis ◽  
Dimensionless Variables ◽  
Disturbance Growth

A new analytical form of dispersion equation which can be used to describe the disturbance growth rate of the diesel bubble growth instability is derived. The instability analysis of vapor bubble growth within the diesel droplet is carried out in this paper. Analysis results show: the disturbance growth rate is majorly influenced by six dimensionless variables. The disturbance growth rate initially decreases gradually then increases rapidly with increasing bubble volume fraction. The disturbance growth rate increases with increasing Weber number of vapor bubble growth, increasing Mach number and increasing diesel droplet Reynolds number. Both vapor bubble Reynolds number and ambient air Reynolds number have slightly influence on disturbance growth rate.

Evaporation Momentum Force on a Bubble Under Asymmetric Temperature Conditions

2014 ◽  
Author(s):  
Pruthvik A. Raghupathi ◽  
Satish G. Kandlikar
Keyword(s):  
Experimental Data ◽  
Growth Rate ◽  
Temperature Field ◽  
Growth Model ◽  
Contact Line ◽  
Bubble Growth ◽  
Recent Literature ◽  
Temperature Conditions ◽  
Boiling Enhancement

Recent literature claims that boiling performance can be significantly improved by using evaporation momentum force to control the trajectory of a bubble. This approach merits a detailed investigation into evaporation momentum force and its effect on bubble growth and bubble trajectory. In this paper an expression for evaporation momentum pressure experienced by a bubble is determined. This is incorporated into a well established bubble growth model (Mikic-Rohsenow) to evaluate the effect of evaporation momentum pressure on bubble growth rate. The effect of evaporation momentum force on a bubble growing in asymmetric temperature field is then studied and the resultant trajectory is evaluated. The results are compared with experimental data of bubble trajectory subjected to an asymmetric temperature condition. The final results suggest that the evaporation momentum pressure in the vicinity of contact line can significantly change the bubble trajectory, and surfaces designed to exploit this effect seem to be promising for boiling enhancement.

Vapor bubble growth with a high value of overheating

2007 ◽  
Vol 5 ◽  
pp. 85-90
Author(s):  
S.P. Aktershev ◽  
V.V. Ovchinnikov
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Satisfactory Agreement ◽  
Vapor Bubble ◽  
Bubble Growth ◽  
Bubble Dynamics ◽  
Bubble Radius ◽  
Temperature Inhomogeneity ◽  
Evaporation Front ◽  
Initial Stage

The numerical simulation of the growth of a vapor bubble in inhomogeneously heated liquid is performed; the influence of the temperature inhomogeneity on the bubble dynamics is investigated. The calculations are compared with experimental data for a vapor bubble growing on a cylindrical heater. At high overheating, the results of the calculations are in satisfactory agreement with experimental data for the initial stage of growth of the vapor bubble. In the presence of evaporation fronts, the measured bubble radius values exceed the calculated values. This excess can be explained by the inflow of vapor to the bubble from the evaporation front.

Prediction Model for Bubble Contact Circle Diameter on Heating Wall

2010 ◽  
Author(s):  
De-qi Chen ◽  
Liang-ming Pan
Keyword(s):  
Experimental Data ◽  
Growth Rate ◽  
Bubble Growth ◽  
Bubble Radius ◽  
Growth Time ◽  
Heating Wall ◽  
Contact Circle ◽  
Proper Values ◽  
Circle Diameter ◽  
Contact Diameter

Phenomenal and theoretical analysis about the evolution of bubble contact circle diameter during bubble growing is presented in current paper; and it is found that bubble contact diameter is dependent on bubble growth rate and bubble radius strongly. By analyzing experimental data from open literature, the relation between dimensionless bubble contact diameter, kw, and dimensionless bubble growth time, t+, is obtained; based on this, a model relative to dimensionless bubble growth rate, dR+/dt+, and dimensionless bubble radius, R+, is proposed for prediction of bubble contact diameter. With proper values for coefficients, aw and nw, this model can well predict experimental data of bubble circle contact diameter in published literatures, with an error within ±20%.

scholarly journals Modeling of vapor bubble growth at subatmospheric pressures

2021 ◽  
Vol 2039 (1) ◽  
pp. 012035
Author(s):  
I V Vladyko ◽  
I P Malakhov ◽  
A S Surtaev ◽  
A A Pil’nik ◽  
A A Chernov
Keyword(s):  
Experimental Data ◽  
Analytical Solution ◽  
Growth Model ◽  
Vapor Bubble ◽  
Bubble Growth ◽  
Numerical Calculations ◽  
Superheated Water ◽  
Thermal Growth ◽  
Simulation Results ◽  
Good Agreement

Abstract In this paper, the results of numerical calculations of a vapor bubble growth in superheated water at different pressures are presented. Modeling is based on a previously developed by the authors semi-analytical solution. The results are verified by experimental data obtained at atmospheric and subatmospheric pressures. The presented simulation results and experimental data are in good agreement. The advantage of the solution over the earlier ones (based on the thermal growth model) is shown.

Numerical Simulation of Growth of a Vapor Bubble During Flow Boiling of Water in a Microchannel

2004 ◽  
Author(s):  
Abhijit Mukherjee ◽  
Satish G. Kandlikar
Keyword(s):  
Growth Rate ◽  
Vapor Bubble ◽  
Bubble Growth ◽  
Stokes Equations ◽  
Flow Boiling ◽  
Thin Liquid Film ◽  
Navier Stokes ◽  
Superheated Liquid ◽  
Navier Stokes Equations ◽  
Energy Equations

The present study is performed to numerically analyze growth of a vapor bubble during flow of water in a microchannel. The complete Navier-Stokes equations along with continuity and energy equations are solved using the SIMPLER method. The liquid vapor interface is captured using the level set technique. The microchannel is 200 microns in square cross-section and the bubble is placed at the center of the channel with superheated liquid around it. The results show steady initial bubble growth followed by a rapid axial expansion after the bubble fills the channel with a thin liquid film around it. The bubble then rapidly turns into a plug and fills up the entire channel. A trapped liquid layer is observed between the bubble and the channel as the plug elongates. The bubble growth rate increased with the incoming liquid superheat and formation of vapor patch at the walls is found to be dependent on the bubble growth rate. The upstream interface of the bubble is found to exhibit both forward and reverse movement during bubble growth. Results show little effect of gravity on the bubble growth under the specified conditions. The bubble growth features obtained from numerical results are found to be qualitatively similar to experimental observations.

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