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

Abstract

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.A good understanding of the liquid droplet dynamics of the spray will help the engineers to design the high efficient facilities under optimized operating parameters. Due to the complex two-phase or multiphase flow and turbulence, normally the flow in spray system is under transient regime [Desantes et al. (2014)]. The time average values of the parameters, such as liquid holdup distributions, liquid phase back mixing, gas-liquid interface disturbing, mass and heat transfer between gas and liquid phases, liquid droplet distributions, liquid droplet velocities etc., have to be considered by the influence of turbulence. Although the operation of spray system is simple, the actual physical flow phenomena are still lack of complete understanding of the fluid dynamics [Husted (2007)].Many experimental facilities and methods were introduced to study the multiphase flows in gas-liquid droplet systems. Ruck and Makiola [1988] used a Laser Doppler anemometer (LDA) to study the gas-oil droplet passing over a backward facing step. Ferrand et al. [2003] used a phase Doppler and Laser induced fluorescence technique to study the gas-droplet turbulent velocity and two-phase interaction through a jet with partly responsive droplets. Esposito et al.[2010] used a monochrome charge-coupled device (CCD) camera to study the growing of the droplets. The experimental methods can provide very useful information about the liquid droplets at certain measurement points, but they are difficult to show the details of the flow fields and parameters inside the spray.Following the development of computer technology, it is already allowed to use the numerical method to do the researches in the recent decades [Shang et al. (2008);Liu et al. (2011);Shang et al. (2012)]. Therefore, many researchers employ the numerical method, called as Computational fluid dynamics (CFD), to study the details of the flows. Griffiths et al. [1996] employed the coupled particle Lagrangian model with Eulerian continual fluid flow model to simulate a cyclone sampler and compared the numerical results with the empirical models. Barton [1999] used the stochastic Monte Carlo scheme coupled with k − ε turbulence model to study the particle trajectories in turbulent flow over a backward facing step. Husted [2007] used the Eulerian-Lagrangian model provided by Fire Dyna...

Influence of design parameters of upstream Venturi pipeline on multiphase flow measurement

“…Many computational fluid dynamics (CFD) studies are conducted on gas-liquid flow. Some of the most common modeling approaches include the Eulerian-Eulerian model (Shu & Wilks, 1995;Yamoah et al, 2015;Zhang et al, 2019;Acharya & Casimiro, 2020), the volume of fluid model (Shu, 2003b;Laleh et al, 2011;López et al, 2016) and the mixture model (Shu et al, 1997;Shu, 2003a;Shang et al, 2015). In this study, the Eulerian-Eulerian model was used as a modeling approach to solve the ensemble-averaged mass and momentum transport equations for dispersed gases, as well as continuous liquids, allowing detailed modeling of phase interactions.…”

Microwave probe sensing location for Venturi-based real-time multiphase flowmeter

“…Many CFD studies have been performed on gas-liquid flow. Some of the most common modeling approaches include the Eulerian-Eulerian model (Shu & Wilks, 1995;Yamoah et al, 2015;Zhang et al, 2019;Acharya & Casimiro, 2020), the volume of fluid model (Frankiewicz et al, 2001;Shu, 2003b;Laleh et al, 2011;López et al, 2016), and the mixture model (Hallanger et al, 1996;Shu et al, 1997;Shu, 2003a;Shang et al, 2015). In this study, the Eulerian-Eulerian model is used as a modeling approach to solve the ensemble-averaged mass and momentum transport equations for dispersed gases and continuous liquids, allowing the details of phase interaction forces to be modeled.…”