Liquid Droplet Entrainment in Reduced and Normal Gravity Two-Phase Flows

2008 ◽  
Author(s):  
Viatcheslav Naoumov ◽  
Masood Parang ◽  
Adam Bowen
Keyword(s):  
Normal Gravity ◽  
Liquid Droplet ◽  
Two Phase Flows ◽  
Two Phase ◽  
Droplet Entrainment

A New Multidimensional Drift Flux Mixture Model for Gas–Liquid Droplet Two-Phase Flow

2015 ◽  
Vol 12 (04) ◽  
pp. 1540001 ◽  
Author(s):  
Zhi Shang ◽  
Jing Lou ◽  
Hongying Li
Keyword(s):  
Mixture Model ◽  
Liquid Droplet ◽  
Diffusion Flux ◽  
Water Mist ◽  
Liquid Droplets ◽  
Two Phase Flows ◽  
Two Phase ◽  
Drift Flux Model ◽  
Drift Flux ◽  
Flux Model

A new multidimensional drift flux mixture model was developed to simulate gas–liquid droplet two-phase flows. The new drift flux model was modified by considering the centrifugal force on the liquid-droplets. Therefore the traditional 1D drift flux model was upgraded to multidimension, 2D and 3D. The slip velocities between the continual phase (gas) and the dispersed phase (liquid droplets) were able to calculate through the multidimensional diffusion flux velocities based on the new modified drift flux model. Through the numerical simulations comparing with the experiments and the simulations of other models on the backward-facing step and the water mist spray two-phase flows, the new model was validated.

Modeling of Falling Film in Vertical Downward Two-Phase Pipe Flow

2012 ◽  
Author(s):  
Jose M. Lopez ◽  
Ram Mohan ◽  
Ovadia Shoham ◽  
Luis Gomez ◽  
Gene Kouba
Keyword(s):  
Film Thickness ◽  
Liquid Film ◽  
Liquid Droplet ◽  
Mechanistic Model ◽  
Mineral Oil ◽  
Liquid Film Thickness ◽  
Falling Film ◽  
Two Phase ◽  
Droplet Entrainment ◽  
Falling Liquid Film

Falling liquid films in vertical pipes are found in a variety of different industrial applications and industrial equipment, such as downcomers, caisson separators and reactors. The hydrodynamics of the falling film in vertical two-phase pipe flow can affect droplet entrainment, gas entrainment, and pressure drop. Therefore, a mechanistic model for prediction of falling liquid film thickness, falling liquid film velocity and a correlation for liquid droplet entrainment fraction in vertical downward liquid-gas systems has been proposed. The falling film model developed is based on applying momentum balance on the liquid film. The liquid film is assumed to be in steady-state, incompressible and free of entrained gas. The mechanistic model includes both the developing and the developed regions. The shear effect between the gas core and the falling liquid film is considered. The liquid droplet entrainment fraction traveling in the gas core is considered and a new correlation for its prediction is proposed. Detailed uncertainty analysis is performed for liquid film thickness and liquid film velocity model predictions, including Monte Carlo simulation. Predicted liquid film thickness, liquid film velocity and liquid droplet entrainment fraction are validated against experimental data for different liquid fluid properties, such as water, Conosol mineral oil (light oil) and Drake mineral oil (heavy oil).

A Physical Model for Predicting Annular Film Flow Droplet Entrainment in Heat Transfer Systems

2002 ◽  
Author(s):  
M. J. Holowach ◽  
L. E. Hochreiter ◽  
F. B. Cheung
Keyword(s):  
Heat Transfer ◽  
Film Flow ◽  
Liquid Droplet ◽  
Flow Analysis ◽  
Interfacial Instability ◽  
Force Balance ◽  
Interfacial Instabilities ◽  
Two Phase ◽  
Droplet Entrainment ◽  
Annular Film

The ability to accurately predict droplet entrainment in annular two-phase flow is required to effectively calculate the interfacial mass, momentum, and energy transfer, which characterizes nuclear reactor safety, system design, analysis, and performance. Most annular flow entrainment models in the open literature are formulated in terms of dimensionless groups, which do not directly account for interfacial instabilities. However, many researchers agree that there is a clear presence of interfacial instability phenomena having a direct impact on droplet entrainment. The present study proposes a model for droplet entrainment, based on the underlying physics of droplet entrainment from co-current upward annular film flow that is characteristic to Light Water Reactor (LWR) safety analysis. The model is developed based on force balance and a stability analysis that can be implemented into a transient three-field (continuous liquid, droplet, and vapor) two-phase heat transfer and fluid flow analysis computer code.

Control of wetness fraction and liquid droplet size in wet steam two phase flows with hot steam injection

Meccanica ◽  
2017 ◽  
Vol 53 (1-2) ◽  
pp. 193-207 ◽  
Author(s):  
Mohadeseh Sadat Mirhoseini ◽  
Masoud Boroomand
Keyword(s):  
Droplet Size ◽  
Liquid Droplet ◽  
Steam Injection ◽  
Wet Steam ◽  
Two Phase Flows ◽  
Two Phase
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