Direct numerical simulation of a turbulent bubbly flow in a vertical channel: Towards an improved second-order reynolds stress model

2017 ◽  
Vol 321 ◽  
pp. 92-103 ◽  
Author(s):  
Guillaume Bois
Keyword(s):  
Numerical Simulation ◽  
Direct Numerical Simulation ◽  
Reynolds Stress ◽  
Bubbly Flow ◽  
Vertical Channel ◽  
Reynolds Stress Model ◽  
Second Order ◽  
Stress Model

scholarly journals Study on bubble-induced turbulence in pipes and containers with Reynolds-stress models

2022 ◽  
Author(s):  
Yixiang Liao ◽  
Tian Ma
Keyword(s):  
Numerical Simulation ◽  
Reynolds Stress ◽  
Large Scale ◽  
Bubbly Flow ◽  
Reynolds Stress Model ◽  
Viscosity Models ◽  
Stress Components ◽  
Specific Source ◽  
Stress Models ◽  
Made In

AbstractBubbly flow still represents a challenge for large-scale numerical simulation. Among many others, the understanding and modelling of bubble-induced turbulence (BIT) are far from being satisfactory even though continuous efforts have been made. In particular, the buoyancy of the bubbles generally introduces turbulence anisotropy in the flow, which cannot be captured by the standard eddy viscosity models with specific source terms representing BIT. Recently, on the basis of bubble-resolving direct numerical simulation data, a new Reynolds-stress model considering BIT was developed by Ma et al. (J Fluid Mech, 883: A9 (2020)) within the Euler—Euler framework. The objective of the present work is to assess this model and compare its performance with other standard Reynolds-stress models using a systematic test strategy. We select the experimental data in the BIT-dominated range and find that the new model leads to major improvements in the prediction of full Reynolds-stress components.

An Eddy-Resolving Reynolds Stress Model for the Turbulent Bubbly Flow in a Square Cross-Sectioned Bubble Column

2014 ◽  
Author(s):  
Matthias Ullrich ◽  
Benjamin Krumbein ◽  
Robert Maduta ◽  
Suad Jakirlić
Keyword(s):  
Reynolds Stress ◽  
Bubble Column ◽  
Bubbly Flow ◽  
Three Dimensional ◽  
Reynolds Stress Model ◽  
Moment Closure ◽  
Numerical Code ◽  
Stress Model ◽  
Mean Flow ◽  
Second Moment Closure

An instability-sensitive, eddy-resolving Reynolds Stress Model of turbulence, employed in the Eulerian-Eulerian two-fluid framework, is formulated and validated by computing the gas-liquid bubble column in a three-dimensional square cross-sectioned configuration in the homogeneous flow regime. Interphase momentum transfer is modelled by considering drag, lift and virtual mass forces. The turbulence in the continuous liquid phase is captured by using a Second-Moment Closure model employed in the Unsteady Reynolds-Averaged Navier Stokes framework implying the solving of the differential transport equations for the Reynolds stress tensor and the homogeneous part of the inverse turbulent time scale ωh. This uiuj – ωh model is appropriately extended in accordance with the Scale-Adaptive Simulation proposal, enabling so the development of the fluctuating turbulence. The results obtained are analysed along with a reference experiment with respect to the evolution of the mean flow and turbulent quantities in both gas and liquid phases. The model described is implemented in the numerical code OpenFOAM.

Numerical study of turbulent round jet in a uniform counterflow using a second order Reynolds Stress Model

2015 ◽  
Vol 9 (4) ◽  
pp. 482-495 ◽  
Author(s):  
Amani Amamou ◽  
Sabra Habli ◽  
Nejla Mahjoub Saïd ◽  
Philippe Bournot ◽  
Georges Le Palec
Keyword(s):  
Reynolds Stress ◽  
Numerical Study ◽  
Reynolds Stress Model ◽  
Second Order ◽  
Stress Model ◽  
Round Jet

The Effect of Compressibility on Turbulent Shear Flow: Direct Numerical Simulation Study

2013 ◽  
Vol 135 (10) ◽  
Author(s):  
Aicha Hanafi ◽  
Hechmi Khlifi ◽  
Taieb Lili
Keyword(s):  
Numerical Simulation ◽  
Shear Flow ◽  
Direct Numerical Simulation ◽  
Reynolds Stress ◽  
Simulation Study ◽  
Structural Evolution ◽  
Second Order ◽  
Turbulent Shear ◽  
Turbulent Shear Flow ◽  
Wide Range

The study of the phenomenon of compressibility for modeling to second order has been made by several authors, and they concluded that models of the pressure-strain are not able to predict the structural evolution of the Reynolds stress. In particular studies and Simone Sarkar et al., a wide range of initial values of the parameters of the problem are covered. The observation of Sarkar was confirmed by the study of Simone et al. (1997,“The Effect of Compressibility on Turbulent Shear Flow: A Rapid Distortion Theory and Direct Numerical Simulation Study,” J. Fluid Mech., 330, p. 307;“Etude Théorique et Simulation Numérique de la Turbulence Compressible en Présence de Cisaillement où de Variation de Volume à Grande Échelle” thése, École Centrale de Lyon, France). We will then use the data provided by the direct simulations of Simone to discuss the implications for modeling to second order. The performance of different variants of the modeling results will be compared with DNS results.

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