[subhojitkadiacfd]

Hello Everyone,
I am working on very simple steady state solution (2D) of a channel flow using simpleFoam and having single cell along the flow direction (x).
I have used periodic boundary condition for inlet and outlet, noSlip (for U) for the walls. I have tried different available fvSchemes.
However, getting checkerboarding issue with p, Uy and Uz.
Any suggestions to eliminate the issue will be highly appreciated. Thanks.

Subho

[piu58]

First: Periodic b.c. often lead to problems. You are in 2D. It may be much better stacking some of the geometries and avoid periodicity in b.c.
Second: Checkerboarding is an issue of Mesh, may be combined with schemes. Try using a finer mesh.

[subhojitkadiacfd]

Many thanks for your reply Uwe. In my case, I have restrict to a 2D simulation. I have used fine mesh.

Subhojit

[piu58]

In most cases, the main question is not
How may I get my simulation running
but
How do I change my real world problem into a simulation.

> I have restrict to a 2D simulation

Normally, there are no such restrictions. We have to select the simulation which gives the most reliable results. Often, this is the simplest one.

If you want to stay your simulation, I recommend using more stable schemes and relaxation.

[subhojitkadiacfd]

Hello Uwe,
Thanks for your reply. I am using the following schemes

ddtSchemes
{
    default         steadyState;
}

gradSchemes
{
    default 		Gauss linear; //cellLimited Gauss linear 1;
}

divSchemes
{
    default				none;
	div(phi,U)  		bounded Gauss limitedLinearV 1;//bounded Gauss linearUpwind grad(U);
    div(phi,k)      	bounded Gauss limitedLinear 1;
    div(phi,epsilon) 	bounded Gauss limitedLinear 1;
	div((nuEff*dev2(T(grad(U))))) Gauss linear;
    div((nu*dev2(T(grad(U))))) Gauss linear;//For LRR, SSG
	div(phi,R)      	bounded Gauss limitedLinear 1; //For LRR, SSG
    div(R)          	Gauss linear; //For LRR, SSG
}

laplacianSchemes
{
    //default         Gauss linear corrected;
	default 		Gauss linear orthogonal;
}

interpolationSchemes
{
    default 		linear;
	//interpolate(U) 	linear;
}

snGradSchemes
{
    //default         corrected;
	default 		orthogonal;
}

fluxRequired
{
	default	no;
	p;
}

wallDist
{
	method			meshWave;
}

Relaxation:
for p 0.3 and for rest 0.7. I have also tried with lower/higher relaxations.
But no noticeable improvements.

Subhojit

Originally Posted by piu58

In most cases, the main question is not
How may I get my simulation running
but
How do I change my real world problem into a simulation.

> I have restrict to a 2D simulation

Normally, there are no such restrictions. We have to select the simulation which gives the most reliable results. Often, this is the simplest one.

If you want to stay your simulation, I recommend using more stable schemes and relaxation.