Prediction of the Flow Around an Airfoil Using a Reynolds Stress Transport Model

1995 ◽  
Vol 117 (1) ◽  
pp. 50-57 ◽  
Author(s):  
Lars Davidson
Keyword(s):  
Experimental Data ◽  
Reynolds Stress ◽  
Transport Model ◽  
Suction Side ◽  
Equation Model ◽  
Staggered Grid ◽  
Poor Agreement ◽  
Third Order ◽  
Reynolds Stress Transport Model ◽  
Quick Scheme

A second-moment Reynolds Stress Transport Model (RSTM) is used in the present work for computing the flow around a two-dimensional airfoil. An incompressible SIMPLEC code is used, employing a non-staggered grid arrangement. A third-order QUICK scheme is used for the momentum equations, and a second-order, bounded MUSCL scheme is used for the turbulent quantities. As the RSTM is valid only for fully turbulent flow, an eddy viscosity, one-equation model is used near the wall. The two models are matched along a preselected grid line in the fully turbulent region. Detailed comparisons between calculations and experiments are presented for an angle of attack of α = 13.3 deg. The RSTM predictions agree well with the experiments, and approaching stall is predicted for α = 17 deg, which agrees well with experimental data. The results obtained with a two-layer κ – ∈ model show poor agreement with experimental data; the velocity profiles on the suction side of the airfoil show no tendency of separation, and no tendency of stall is predicted.

Numerical Simulation of Separation Control in Backward Facing Step Turbulent Flow

2002 ◽  
Author(s):  
Emmanuel Guilmineau ◽  
Patrick Queutey
Keyword(s):  
Experimental Data ◽  
Reynolds Stress ◽  
Transport Model ◽  
Turbulence Models ◽  
Separated Flow ◽  
Separation Control ◽  
Local Perturbation ◽  
Backward Facing Step ◽  
Reynolds Stress Transport Model ◽  
Turbulent Separated Flow

The control of turbulent separated flow over the backward-facing step is numerically investigated with various turbulence models ranging from one equation Spalart & Allmaras (1992), two-equation K-ω closures (Wilcox, 1988; Menter, 1993) to a full Reynolds stress transport model based on the Reynolds stress transport Rij-ω model (Deng & Visonneau, 1999). Results are compared with experimental data of Yoshioka et al. (1999) where the flow control was monitoring with alternating suction/injection at the step height. It is shown that the effect of that local perturbation is better represented using the Rij-ω turbulence model.

Numerical investigation of flow features in the vaneless region of a centrifugal pump by large eddy simulation

2018 ◽  
Vol 35 (1) ◽  
pp. 395-410 ◽  
Author(s):  
Xianbei Huang ◽  
Yaojun Li ◽  
Zhuqing Liu ◽  
Wei Yang
Keyword(s):  
Experimental Data ◽  
Transport Equation ◽  
Centrifugal Pump ◽  
Reynolds Stress ◽  
Pressure Pulsation ◽  
Third Order ◽  
Production Term ◽  
Content Type ◽  
Blade Passing Frequency ◽  
Rotor Stator Interaction

Purpose The purpose of this paper is to obtain a better understanding of the rotor–stator interaction in the vaneless region of a centrifugal pump. Design/methodology/approach A third-order sub-grid scale (SGS) model containing the rotation rate tensor named the dynamic cubic non-linear model (DCNM) is used for simulating the flow field in a centrifugal pump with a vaned diffuser. The pressure coefficient and velocity distributions are compared with the experimental data. Focusing on the vaneless region, the pressure pulsation, Reynolds stress pulsation and Reynolds stress transport equation are analyzed. Findings The comparison of the calculation results with the experimental data indicates that the DCNM can accurately capture the distributions of pressure and velocity in the vaneless region. Based on the instantaneous pressure signals, the pressure pulsation is analyzed to show that in the vaneless region, the dominant frequency near the impeller is twice the blade passing frequency, whereas it is equal to the blade passing frequency near the diffuser. Further exploration of the Reynolds stress pulsation shows the correlation between the two variables. Additionally, the extreme low frequency of Reynolds stress near the diffuser is found to be related to the rotation instability. To explore the turbulence characteristics in the vaneless region, the Reynolds stress transportation equation is studied. In the vaneless region, the rotation term of the Reynolds stress transport equation is negligible compared to the production term, although the rotation instability is obvious near the diffuser. The production of the Reynolds stress plays the role of redistributing the energy from the uu component to the vv component, except for the region near the impeller outlet. Originality/value The third-order SGS model DCNM has proved to be promising in simulating the rotor–stator interaction. The analysis of the rotation instability and the Reynolds stress transport equation shed light on the further understanding of the rotor–stator interaction.

scholarly journals A Second-Order Turbulence Model Based on a Reynolds Stress Approach for Two-Phase Flow—Part I: Adiabatic Cases

2009 ◽  
Vol 2009 ◽  
pp. 1-14 ◽  
Author(s):  
S. Mimouni ◽  
F. Archambeau ◽  
M. Boucker ◽  
J. Laviéville ◽  
C. Morel
Keyword(s):  
Liquid Phase ◽  
Reynolds Stress ◽  
Turbulence Model ◽  
Two Phase Flow ◽  
Turbulence Modeling ◽  
Transport Model ◽  
Phase Flow ◽  
Two Phase ◽  
Model Based ◽  
Reynolds Stress Transport Model

In our work in 2008, we evaluated the aptitude of the code Neptune_CFD to reproduce the incidence of a structure topped by vanes on a boiling layer, within the framework of the Neptune project. The objective was to reproduce the main effects of the spacer grids. The turbulence of the liquid phase was modeled by a first-orderK-εmodel. We show in this paper that this model is unable to describe the turbulence of rotating flows, in accordance with the theory. The objective of this paper is to improve the turbulence modeling of the liquid phase by a second turbulence model based on aRij-εapproach. Results obtained on typical single-phase cases highlight the improvement of the prediction for all computed values. We tested the turbulence modelRij-εimplemented in the code versus typical adiabatic two-phase flow experiments. We check that the simulations with the Reynolds stress transport model (RSTM) give satisfactory results in a simple geometry as compared to aK-εmodel: this point is crucial before calculating rod bundle geometries where theK-εmodel may fail.

Reynolds Stress Transport Model Predictions and Large Eddy Simulations for Film Coolant Jet in Crossflow

2000 ◽  
Author(s):  
Asif Hoda ◽  
Sumanta Acharya ◽  
Mayank Tyagi
Keyword(s):  
Flow Field ◽  
Reynolds Stress ◽  
Transport Model ◽  
Large Eddy Simulations ◽  
Complex Flow ◽  
Navier Stokes Equation ◽  
Reynolds Stress Transport Model ◽  
Jet In Crossflow ◽  
Turbulent Statistics ◽  
Large Eddy

Predictions of a film coolant jet in a crossflow for turbine blade cooling applications have traditionally employed k-ε and k-ω closure models of turbulence. An evaluation of several such models (Hoda and Acharya, 1999) revealed that the existing two equation models fail to resolve the highly complex flow field in the vicinity of the jet created by the jet-crossflow interaction. The eddy viscosity approximation used to obtain closure for the Reynolds stress terms in the time-averaged Navier Stokes equation is unable to represent the anisotropy of the flow and does not model the wake region created behind the jet adequately. A more accurate prediction of the stress field can be obtained by the Reynolds stress transport (RST) equations, which represent a higher level of closure for the turbulent stresses. In this paper, two formulations of the RST model have been employed to predict the flow behind a row of jets discharging normally into a crossflow. The flow field predictions and turbulent statistics are compared with the experimental data of Ajersch et al. (1995) and with k-ε predictions using the model of Lam and Bremhorst (1981). Predictions using Large Eddy Simulations (LES) are also presented to show the predictive capability of LES.

Reynolds Stress Turbulence Models for Prediction of Shear Stress Terms in Cross Flow Film Cooling — Numerical Simulation

2002 ◽  
Author(s):  
Aliyar Javadi ◽  
Khodayar Javadi ◽  
Mohamad Taeibi-Rahni ◽  
Mohammad Reza Keimasi
Keyword(s):  
Numerical Simulation ◽  
Shear Stress ◽  
Reynolds Stress ◽  
Turbulence Model ◽  
Film Cooling ◽  
Model Comparison ◽  
Transport Model ◽  
Staggered Grid ◽  
Computational Domain ◽  
Sst Turbulence Model

Reynolds stress models are computationally more complex and time consuming but, have the potential of greater accuracy and wider applicability. Turbulent cross flows and film cooling have highly complex characteristics. In this work, we computationally simulated a three-dimensional, separated hole film cooling problem of flow over a flat plate, using Reynolds stress model (RSM) with wall function and zonal (κ-ε)/(κ-ω) turbulence model (shear stress transport model or SST). The Reynolds number of the jet was 4700. Our computational domain included the space above plate plus the film cooling jet channel. In our numerical simulation, the SIMPLE finite volume method with a non-uniform staggered grid was implemented. Our results were compared with Ajersch et al. experimental and numerical work’s (κ-ε turbulence model). Also, they were compared with Keimasi and Taeibi-Rahani’s numerical simulation work (SST turbulence model). Comparison between the measured and computed results show, that RSM/SST turbulence model in our work has better agreement with experimental data in most cases.

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