Difference between revisions of "Sig Turbulence / Channel Flow"

Latest revision as of 10:06, 5 November 2012

Olivier Brugiere, Universite Joseph Fourier, Grenoble, France

1 Motivation

Test avaiable subgrid scale (SGS) model
Test wall model on easy configuration:
- no pressure gradients
- cheap calculation
- easy to mesh
- ...
Many DNS data base can be found (ex: the Kawmura laboratory [[1]]) to compare mean velocity and rms profiles

2 Testcase description

2.1 Flow configuration

2.1.1 Boundary condition

Figure 1 : Flow configuration

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

2.1.2 Geometrical Parameters

The Reynodls number of the flow is the same as Abe et al. [3] ( $Re_{\tau} = 1020$ ). Thus the geometry is :

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

2.2 Mesh generation

Figure 2 : Mesh for y+ = 200

We have done the mesh with an automatic tool (*.m4) which is composed by $Nx * Ny * Nz = 50 * 40 * 38$ . The mesh is composed by 4 blocks:

2 blocks for the first cell close to the wall. (Hense, y+ can be imposed)
2 blocks in the center

2.3 Simulation details

The aim of my study is testing a posteriori near-wall law. We are running three cases :

Without wall model
With the Spalding law [1]
With the Manhart et al. law [2]

3 Numerical results

Results of the simulations are available in the paper written by Duprat et al. [4]

4 References

[1] Spalding, 1961, A single formula for the law of the wall, J. 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.

[4] Duprat, Balarac, Métais, Congedo, and Brugière, 2011, A wall-layer model for large-eddy simulations of turbulent flows with/out pressure gradient. Physics of Fluids, 23, 015101.[2]

Back to Validation test cases

@@ Line 3: / Line 3: @@
 == Motivation ==
-[[File:Hilloutlined.jpg|thumb|Figure 1 : Periodic hill]]
+* Test avaiable subgrid scale (SGS) model
-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 [[http://murasun.me.noda.tus.ac.jp/turbulence/]]. You can compare your mean velocity profile and the rms velocity with the data base.
+* Test wall model on easy configuration:
+** no pressure gradients
+** cheap calculation
+** easy to mesh
+** ...
+*Many DNS data base can be found (ex: the Kawmura laboratory [[http://murasun.me.noda.tus.ac.jp/turbulence/]]) to compare mean velocity and rms profiles
 == Testcase description ==
 === Flow configuration ===
+==== Boundary condition ====
+[[File:Canal.jpg|thumb|Figure 1 : Flow configuration]]
+* Streamwise condition : periodicity
+* Spanwise condition : periodicity
+* Normal to streamwise : two walls
 ==== Geometrical Parameters ====
+The Reynodls number of the flow is the same as Abe et al. [3] (<math> Re_{\tau} = 1020</math>). Thus the geometry is :
 * Streamwise distance : <math>L_{x} = 12,8 h</math>
@@ Line 16: / Line 29: @@
 * Spanwise distance  : <math>L_{y} = 6,4 h</math>
-==== Boundary condition ====
+=== Mesh generation ===
+[[File:Meshy200.jpg|thumb|Figure 2 : Mesh for y+ = 200]]
-* Streamwise condition : periodicity
+We have done the mesh with an automatic tool ([[Sig Turbulence / channelBlockMeshDict |*.m4]]) which is composed by <math>Nx * Ny * Nz = 50 * 40 * 38 </math>.
-* Spanwise condition : periodicity
+The mesh is composed by 4 blocks:
-* Normal to streamwise : two walls
+* 2 blocks for the first cell close to the wall. (Hense, y+ can be imposed)
+* 2 blocks in the center
 === Simulation details ===
-We have make the geometry with canalrectangulaireperiodic.m4 and the mesh is composed by <math>Nx \times Ny \times Nz = 50 \times 40 \times38</math>.
+The aim of my study is testing a posteriori near-wall law. We are running three cases :
-The aim of my study is testing a posteriori near-wall low. To compare we are running three cases :
+* Without wall model
+* With the Spalding law [1]
-* With near-wall low
+* With the Manhart et al. law [2]
-* 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] [[http://murasun.me.noda.tus.ac.jp/turbulence/poi/text/Poi1020_4th_A_ver2.dat]]
 == Numerical results ==
+Results of the simulations are available in the paper written by Duprat et al. [4]
 == References ==
-[1] Spalding, 1961, A single formula for the law of the wall, Jl. Appl. Mech., vol 28, pp. 455-457
+[1] Spalding, 1961, A single formula for the law of the wall, J. 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.
+[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 <math>Re_{\tau} = 1020</math> with Pr = 0,025 and 0,71, 2004, Int. J. Heat and Fluid Flow, vol 25, pp. 404-419.
-Back to [[Sig Turbulence]]
+[4] Duprat, Balarac,  Métais, Congedo, and Brugière, 2011, A wall-layer model for large-eddy simulations of turbulent flows with/out pressure gradient. Physics of Fluids, 23, 015101.[http://pof.aip.org/resource/1/phfle6/v23/i1/p015101_s1]
+Back to [[Sig Turbulence / Validation test cases|Validation test cases]]