Transient simulation for large scale flow in bubble columns

The transient simulation of large scale bubbly flow in bubble columns using the unsteady Reynolds averaged Navier Stokes (URANS) equations is investigated in the present paper. An extensive set of bubble forces is used with different models for the bubble induced turbulence. Criteria are given to assess the independence of the simulation time and the time step length. Using these criteria it is shown that a simulation time, time step length and mesh independent solution can be obtained for complex bubbly flows using URANS equations under certain requirements. With the obtained setup the contribution of the resolved turbulence to the total turbulence and the influence of the bubble induced turbulence modeling on the resolved turbulence is investigated. Further, it is pointed out that the virtual mass force is not negligible. The simulations are compared to data from the literature at two different superficial velocities, which cover monodisperse and polydisperse bubbly flows.

[1]  N. Zuber,et al.  Drag coefficient and relative velocity in bubbly, droplet or particulate flows , 1979 .

[2]  Akio Tomiyama,et al.  On the role of the lateral lift force in poly-dispersed bubbly flows , 2011 .

[3]  L. Hernández,et al.  Hydrodynamic characterization of a needle sparger rectangular bubble column: Homogeneous flow, static bubble plume and oscillating bubble plume , 2007 .

[4]  A. K. Agrawal,et al.  Shape of liquid drops moving in liquid media , 1966 .

[5]  Eckhard Krepper,et al.  The inhomogeneous MUSIG model for the simulation of polydispersed flows , 2008 .

[6]  Eckhard Krepper,et al.  Development of a generalized coalescence and breakup closure for the inhomogeneous MUSIG model , 2011 .

[7]  Antonio Delgado,et al.  Numerical investigation of the interphase forces and turbulence closure in 3D square bubble columns , 2014 .

[8]  Eckhard Krepper,et al.  Numerical Simulation of Polydispersed Flow in Bubble Columns with the Inhomogeneous Multi‐Size‐Group Model , 2013 .

[9]  Jyeshtharaj B. Joshi,et al.  Hydrodynamic stability of multiphase reactors , 2001 .

[10]  Carlos A. Dorao,et al.  Modeling of Bubble Column Reactors: Progress and Limitations , 2005 .

[11]  Gerhart Eigenberger,et al.  Applicability of the standard k–ε turbulence model to the dynamic simulation of bubble columns: Part I. Detailed numerical simulations , 1999 .

[12]  I. Zun,et al.  Effects of Eötvös Number and Dimensionless Liquid Volumetric Flux on Lateral Motion of a Bubble in a Laminar Duct Flow , 1995 .

[13]  P. Spalart.  Strategies for turbulence modelling and simulations , 2000 .

[14]  Eckhard Krepper,et al.  CFD modelling of polydispersed bubbly two-phase flow around an obstacle , 2009 .

[15]  J. Magnaudet,et al.  The generalized Kirchhoff equations and their application to the interaction between a rigid body and an arbitrary time-dependent viscous flow , 2002 .

[16]  Dieter Bothe,et al.  VOF‐Simulation of the Lift Force for Single Bubbles in a Simple Shear Flow , 2006 .

[17]  B. Launder,et al.  The numerical computation of turbulent flows , 1990 .

[18]  Akio Tomiyama,et al.  Lateral Migration of Single Bubbles Due to the Presence of Wall , 2002 .

[19]  Y. Liao,et al.  A literature review on mechanisms and models for the coalescence process of fluid particles , 2010 .

[20]  Mandar Tabib,et al.  CFD simulation of bubble column—An analysis of interphase forces and turbulence models , 2008 .

[21]  Robert F. Mudde,et al.  Gravity-driven bubbly flows , 2005 .

[22]  Annalisa Manera,et al.  Influence of the lift force on the stability of a bubble column , 2005 .

[23]  C. Lifante,et al.  Comparative study of wall-force models for the simulation of bubbly flows , 2012 .

[24]  Eckhard Krepper,et al.  Closure relations for CFD simulation of bubble columns , 2014 .

[25]  Tadashi Sakaguchi,et al.  Drag Coefficients of Single Bubbles under Normal and Micro Gravity Conditions , 1998 .

[26]  I. Zun,et al.  The transverse migration of bubbles influenced by walls in vertical bubbly flow , 1980 .

[27]  Eckhard Krepper,et al.  Closure models for turbulent bubbly flows: A CFD study , 2013 .

[28]  Michio Sadatomi,et al.  Momentum and heat transfer in two-phase bubble flow—I. Theory , 1981 .

[29]  Eckhard Krepper,et al.  CFD modeling of bubble-induced turbulence , 2013 .

[30]  Jyeshtharaj B. Joshi,et al.  CFD simulations of bubble column reactors: 1D, 2D and 3D approach , 2005 .

[31]  Akio Tomiyama,et al.  BUBBLE TRACKING SIMULATION OF BUBBLE-INDUCED PSEUDOTURBULENCE , 2012 .

[32]  Jyeshtharaj B. Joshi,et al.  Coherent flow structures in bubble column reactors , 2002 .