Residual-based closure model for density-stratified incompressible turbulent flows

A proper orthogonal decomposition (POD) technique has been successfully employed to develop reduced-order models for flow control purposes. For complex flows, higher POD modes also play a significant role in the stability and accuracy of the reduced-order model, thus require a closure, as in turbulent flows. In the presence of nonhomogeneous boundary conditions, developing a closure model becomes a challenging task. This paper discusses nonlinear closure modeling approaches for homogeneous and nonhomogeneous boundary conditions. Burgers’ equations, both one-dimensional and two-dimensional, are considered as the governing equations to develop reduced-order models with different boundary conditions. Homogeneous and nonhomogeneous boundary conditions are considered to demonstrate the effectiveness of the proposed closure modeling technique in boundary control applications. Numerical results show that the proposed closure model improves the accuracy of the reduced-order model.

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Proposal of a Second-Order Closure Model for Homogeneous Turbulent Flows.

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series B ◽

10.1299/kikaib.59.3040 ◽

1993 ◽

Vol 59 (566) ◽

pp. 3040-3047 ◽

Cited By ~ 1

Author(s):

Eiji Ishii ◽

Hiroshi Kawamura

Keyword(s):

Turbulent Flows ◽

Second Order ◽

Closure Model

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Two-Dimensional Simulation of Flows in an Open Channel with Groin-Like Structures by iRIC Nays2DH

Mathematical Problems in Engineering ◽

10.1155/2017/1275498 ◽

2017 ◽

Vol 2017 ◽

pp. 1-10 ◽

Cited By ~ 4

Author(s):

Md. Shahjahan Ali ◽

Md. Milon Hasan ◽

Masuma Haque

Keyword(s):

Shear Stress ◽

Turbulent Flows ◽

Open Channel ◽

Maximum Velocity ◽

Bed Shear Stress ◽

Closure Model ◽

Turbulence Closure Model ◽

Lateral Distance ◽

Stress Profiles ◽

Dimensional Simulation

This study presents the results obtained from the numerical simulation on turbulent flows around a single groin for different orientations. Here iRIC Nays2DH, which is based on 2D model, is used to simulate the flows in a straight open channel with groin of 45°, 90°, and 135° angled with the approaching flow. A depth-averaged k-ε model is used as turbulence closure model with finite differential advections as upwind scheme. The numerical results of velocity and bed shear stress profiles are compared with the available experimental data. Good agreements are found between experimental and calculated results. From the simulation, it is observed that the peak of velocity and bed shear stress is maximum at the position of head of groin when lateral distance y/l=1, where l is the groin length. The position of maximum velocity and bed shear stress is found to be shifted towards downstream with increasing y/l. The maximum velocity and bed shear stress for 135° groin are found lower than the other two cases for all the sections of y/l.

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An extension of the second moment closure model for turbulent flows over macro rough walls

International Journal of Heat and Fluid Flow ◽

10.1016/j.ijheatfluidflow.2019.04.003 ◽

2019 ◽

Vol 77 ◽

pp. 186-201 ◽

Cited By ~ 1

Author(s):

Y. Kuwata ◽

K. Suga ◽

Y. Kawaguchi

Keyword(s):

Turbulent Flows ◽

Moment Closure ◽

Closure Model ◽

Second Moment ◽

Rough Walls ◽

Second Moment Closure

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CONVERGENCE ANALYSIS OF THE FINITE ELEMENT METHOD FOR A FUNDAMENTAL MODEL IN TURBULENCE

Mathematical Models and Methods in Applied Sciences ◽

10.1142/s0218202512500339 ◽

2012 ◽

Vol 22 (11) ◽

pp. 1250033 ◽

Cited By ~ 9

Author(s):

S. KAYA ◽

C. C. MANICA

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Turbulent Flows ◽

The Finite Element Method ◽

Closure Model ◽

Eddy Simulation ◽

Large Structures ◽

Large Eddy ◽

Stability And Accuracy ◽

Element Method

This report is concerned with the question of computing accurate approximations to the motion of large structures in turbulent flows. We choose a fundamental closure model used in Large Eddy Simulation and investigate how a simple finite element method can be used to compute discrete solutions. We determine that both stability and accuracy of the discretization depend strongly on how filtering is performed. A numerical example is provided that supports our theoretical findings.

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