scholarly journals Probing Reynolds stress models of convection with numerical simulations: I. Overall properties: fluxes, mean profiles

2006 ◽  
Vol 2 (S239) ◽  
pp. 80-82 ◽  
Author(s):  
F. Kupka ◽  
H. J. Muthsam
Keyword(s):  
Numerical Simulation ◽  
Temperature Gradient ◽  
Numerical Simulations ◽  
Reynolds Stress ◽  
Simulation Study ◽  
3D Numerical Simulation ◽  
Stellar Convection ◽  
Mean Temperature ◽  
Stress Models

AbstractWe introduce an extended 3D numerical simulation study of Reynolds stress models of stellar convection and probe fluxes as well as mean temperature gradient profiles.

scholarly journals Probing Reynolds stress models of convection with numerical simulations: III. Compressibility modelling and dissipation

2006 ◽  
Vol 2 (S239) ◽  
pp. 86-88 ◽  
Author(s):  
F. Kupka ◽  
H. J. Muthsam
Keyword(s):  
Numerical Simulation ◽  
Kinetic Energy ◽  
Numerical Simulations ◽  
Turbulent Kinetic Energy ◽  
Reynolds Stress ◽  
Simulation Study ◽  
Pressure Fluctuations ◽  
3D Numerical Simulation ◽  
Stellar Convection ◽  
Stress Models

AbstractWe provide results from an extended 3D numerical simulation study of Reynolds stress models of stellar convection and probe the modelling of compressibility, pressure fluctuations, and dissipation of turbulent kinetic energy.

scholarly journals Probing Reynolds stress models of convection with numerical simulations: II. Non-locality and third order moments.

2006 ◽  
Vol 2 (S239) ◽  
pp. 83-85 ◽  
Author(s):  
F. Kupka ◽  
H. J. Muthsam
Keyword(s):  
Numerical Simulation ◽  
Numerical Simulations ◽  
Reynolds Stress ◽  
Simulation Study ◽  
Third Order ◽  
Stellar Convection ◽  
Stress Models ◽  
Non Locality

AbstractWe provide results from an extended numerical simulation study of Reynolds stress models of stellar convection and probe the modelling of third order moments and non-locality.

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.

Numerical Simulation of Thermocapillary Convection in an Annular Pool of Silicone Oil Heated From Inner Wall

2007 ◽  
Author(s):  
Wanyuan Shi ◽  
Nobuyuki Oshima ◽  
Nobuyuki Imaishi
Keyword(s):  
Numerical Simulation ◽  
Critical Temperature ◽  
Temperature Gradient ◽  
Numerical Simulations ◽  
Temperature Difference ◽  
Significant Influence ◽  
Thermocapillary Convection ◽  
Silicone Oil ◽  
Annular Pool ◽  
Surface Temperature Gradient

Thermocapillary convection in a shallow annular pool (depth d = 1 mm) of silicone oil (0.65 cSt, Pr = 6.7), heated from the inner wall, is investigated by numerical simulations. Under a fixed value of temperature difference between the outer and inner walls, surface temperature gradient in the inner heated pool is about 10% higher than that in the outer heated pool. Accordingly, the critical temperature difference for the incipience of HTW (ΔTc = 4.58K) is smaller than that (ΔTc = 5.0K) in the outer heated pool. Numerical simulations indicate that two groups of HTW, propagating in opposite azimuthal directions to each other, coexist and produce interference patterns in the inner heated pool. Rotation of the pool around its axis gives no significant influence on the behavior of HTW in the inner heated pool. The characteristics of HTW are discussed in contrast with those in the outer heated pool.

3D Numerical Simulation of Hydraulics in an Oxidation Ditch

2012 ◽  
Vol 468-471 ◽  
pp. 190-193
Author(s):  
B. Lv ◽  
W.L. Wei ◽  
Y.L. Liu
Keyword(s):  
Numerical Simulation ◽  
Numerical Method ◽  
Turbulence Model ◽  
Simulation Study ◽  
Simple Type ◽  
Oxidation Ditch ◽  
Correction Algorithm ◽  
3D Numerical Simulation ◽  
Numerical Convergence ◽  
Wall Functions

A numerical simulation study of the hydrodynamics of an oxidation ditch is presented. The numerical method is based on a pressure-correction algorithm of the SIMPLE-type. A multigrid technique based on the full approximation storage (FAS) scheme is employed to accelerate the numerical convergence, while as a turbulence model the RNG κ-ε model with wall functions is used. The numerical results for velocity in the oxidation ditch are obtained．

3D Numerical Simulation of Point Impact Breakage of a Glass Ball

2011 ◽  
Vol 299-300 ◽  
pp. 1012-1015
Author(s):  
Yun Chuan Yang ◽  
Xu Wang
Keyword(s):  
Numerical Simulation ◽  
Numerical Simulations ◽  
Stress Waves ◽  
Glass Ball ◽  
3D Numerical Simulation ◽  
Simulation Results

Based on the 3D plane impact and 2D MCA numerical simulation, the 3D ANSYS/LS-DYNA software is applied to conduct numerical simulations on two kinds of impact breaking process of a glass ball, during which spallation phenomenon occur. The Von Misses stress of each node changes with the time as the result of the stress waves spreading, reflecting and overlapping within the material. The stereograms and profiles from the simulation results reveal that the stress of each node changes with the time. By comparing the simulation results of plane impact and 2D point impact, differences and similarities between these processes are illustrated in this paper, which reflects the complexity of mechanics in the processes.

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