A Calculation Method for Developing Turbulent Flow in Rectangular Ducts of Arbitrary Aspect Ratio

1995 ◽  
Vol 117 (2) ◽  
pp. 249-258 ◽  
Author(s):  
M. Naimi ◽  
F. B. Gessner
Keyword(s):  
Reynolds Number ◽  
Turbulent Flow ◽  
Transport Equation ◽  
Reynolds Stress ◽  
Equation Model ◽  
Strain Component ◽  
Square Duct ◽  
Damping Function ◽  
Strain Behavior ◽  
Proposed Model

This paper describes a full Reynolds stress transport equation model for predicting developing turbulent flow in rectangular ducts. The pressure-strain component of the model is based on a modified form of the Launder, Reece and Rodi pressure-strain model and the use of a linear wall damping function. Predictions based on this model are compared with predictions referred to high Reynolds number and low Reynolds number k–ε transport equation models and with experimental data taken in square and rectangular ducts. The results indicate that the proposed model yields improved predictions of primary flow development and Reynolds stress behavior in a square duct. The proposed model also yields Reynolds stress anisotropy and secondary flow levels that are compatible and agree well with experiment, without recourse to a quadratic damping function to model near-wall pressure-strain behavior.

A Priori Analysis of Explicit Algebraic Stress Models for a Turbulent Flow Through a Straight Square Duct

2004 ◽  
Author(s):  
H. Naji ◽  
O. El Yahyaoui ◽  
G. Mompean
Keyword(s):  
Turbulent Flow ◽  
Reynolds Stress ◽  
Stokes Equations ◽  
A Priori ◽  
Proximity Effects ◽  
Navier Stokes ◽  
Wall Region ◽  
Square Duct ◽  
Anisotropy Tensor ◽  
Stress Models

The ability of two explicit algebraic Reynolds stress models (EARSMs) to accurately predict the problem of fully turbulent flow in a straight square duct is studied. The first model is devised by Gatski and Rumsey (2001) and the second is the one derived by Wallin and Johansson (2000). These models are studied using a priori procedure based on data resulting from direct numerical simulation (DNS) of the Navier-Stokes equations, which is available for this problem. For this case, we show that the equilibrium assumption for the anisotropy tensor is found to be correct. The analysis leans on the maps of the second and third invariants of the Reynolds stress tensor. In order to handle wall-proximity effects in the near-wall region, damping functions are implemented in the two models. The predictions and DNS obtained for a Reynolds number of 4800 both agree well and show that these models are able to predict such flows.

Calculation of Fully-Developed Turbulent Flow in Rectangular Ducts With Nonuniform Wall Roughness

1997 ◽  
Vol 119 (3) ◽  
pp. 550-558 ◽  
Author(s):  
M. Naimi ◽  
F. B. Gessner
Keyword(s):  
Reynolds Stress ◽  
Turbulence Models ◽  
Equation Model ◽  
Mean Velocity ◽  
Fully Developed Flow ◽  
Square Duct ◽  
Fully Developed Turbulent Flow ◽  
Flow Situation ◽  
Velocity Turbulence ◽  
Transport Type

The predictive capabilities of four transport-type turbulence models are analyzed by comparing predictions with experimental data for fully-developed flow in (1) a rectangular duct with a step change in roughness on one wall (Case 1), and (2) a square duct with one rib-roughened wall (Case 2). The models include the Demuren-Rodi (DR) k-ε model, the Sugiyama et al. (S) k-ε model, the Launder-Li (LL) Reynolds stress transport equation model, and the differential stress (DS) model proposed recently by the authors. For the first flow situation (Case 1), the results show that the DS model yields improved agreement between predicted and measured primary and secondary mean velocity distributions in comparison to the DR and LL models. For the second flow situation (Case 2), the DS model is superior to the DR and S models for predicting experimentally observed mean velocity, turbulence kinetic energy, and Reynolds stress anisotropy behavior, especially in the vicinity of a corner formed by the juncture of adjacent smooth and rough walls. The results are analyzed in order to explain why the DR model leads to the formation of a spurious secondary flow cell near this corner that is not present in the experimental flow.

Direct simulation of turbulent flow in a square duct: Reynolds‐stress budgets

1994 ◽  
Vol 6 (9) ◽  
pp. 3144-3152 ◽  
Author(s):  
Asmund Huser ◽  
Sedat Biringen ◽  
Ferhat F. Hatay
Keyword(s):  
Turbulent Flow ◽  
Reynolds Stress ◽  
Direct Simulation ◽  
Square Duct ◽  
Stress Budgets

Multi-GPU simulation of turbulent square duct flow under high Reynolds number in lattice Boltzmann method

2020 ◽  
Author(s):  
Limin Wang ◽  
Tao Hu ◽  
Xing Xiang ◽  
Wei Ge
Keyword(s):  
Reynolds Number ◽  
Turbulent Flow ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Reynolds Shear Stress ◽  
Secondary Flows ◽  
Square Duct ◽  
Turbulent Characteristics ◽  
Fully Developed Turbulent Flow ◽  
Boltzmann Method

Abstract Using multi-GPU in lattice Boltzmann method (LBM), fully developed turbulent flow in a square duct at the friction Reynolds numbers (Reτ) of 300, 600, 1200 and 1800 are simulated. Through simulation of three-dimensional lid-driven cavity flow under different Reynolds number (Re), the accuracy of lattice Bhatnager-Gross-Krook (LBGK) multi-GPU program is validated. For turbulent flow in a square duct, all mean velocity, secondary flows, root mean square (rms) of pulsating velocity and Reynolds shear stress predicted by LBGK under the lower Reτ agree well with the literature results, which further verified the effectiveness of the LBGK. In addition, fully developed turbulent flow in a square duct with Reτ up to 1800 predicted by LBGK with 600 million grids provides a reference for turbulent flows under high Reτ . Numerical results show that the LBGK model with low accuracy successfully captures turbulent characteristics for flows at high Re by increasing the grid size, indicating the feasibility and practicality of multi-GPU LBM for modeling industrial flows.

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