Sig Turbulence / Channel Flow

Olivier Brugiere, Universite Joseph Fourier, Grenoble, France

1 Motivation

Figure 1 : Periodic hill

Before start a study on a complex geometry you can test your subgrid scale (SGS) model or your near wall low on a channel flow. You don't have a pressure gradient and it's very ease to test something on this kind of flow. You can find many DNS data base like the DNS form the Kawmura laboratory [[1]]. You can compare your mean velocity profile and the rms velocity with the data base.

2 Testcase description

2.1 Flow configuration

2.1.1 Geometrical Parameters

• Streamwise distance : $L_{x} = 12,8 h$
• Normal wall heigh  : $L_{y} = 2 h$
• Spanwise distance  : $L_{y} = 6,4 h$

2.1.2 Boundary condition

• Streamwise condition : periodicity
• Spanwise condition : periodicity
• Normal to streamwise : two walls

2.2 Simulation details

We have make the geometry with canalrectangulaireperiodic.m4 and the mesh is composed by $Nx \times Ny \times Nz = 50 \times 40 \times38$.

The aim of my study is testing a posteriori near-wall low. To compare we are running three cases :

• With near-wall low
• With the Spalding Low [1]
• With the Mahart et al. low [2]

The Reynodls number of the flow it's the same as Abe et al. [3] [[2]]

4 References

[1] Spalding, 1961, A single formula for the law of the wall, Jl. Appl. Mech., vol 28, pp. 455-457

[2] Manhart Peller and Brun, 2008, Near-wall scaling for turbulent boundary layers with adverse pressure gradient, Theor. Comput. Fluid Dyn., vol 22 , pp. 243-260.

[3] Abe, Kawamura and Matsuo, Surface heat-flux fluctuations in a turbulent channel flow up to $Re_{\tau} = 1020$ with Pr = 0,025 and 0,71, 2004, Int. J. Heat and Fluid Flow, vol 25, pp. 404-419.

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