[Kbshariff]

Hi foamers,

I am having trouble with residuals convergence when I used no slip wall BC in simple foam.

I am simulating a tidal turbine using actuator disc model defined in fvOption in OFv2006.

My case converges with slip walls at the bottom of the domain after say aroud 3000 iteration, but when I used no slip ( because i am using a log profile at inlet for U and I). the residual is still constant for 60,000 iterrations ( about 16 hrs runtime).

I attached herewith by case files please

U/

internalField   uniform (0 0 0);

boundaryField
{

    inlet           
   {
     type            groovyBC;
     variables (
		"zp=pos().z;"
		"a=0.197;"
		"u_f=0.00787;"
		"n=1e-6;"
		"vel=(2.5*u_f*log((u_f*zp)/(n))+a)*normal();"
		);
     valueExpression "-vel";

   }



    	outlet
    		{
       			type            zeroGradient;
    		}

	top
		{
			type		symmetry;
		}
	
	bottom
		{
			type		fixedValue;
			value		uniform (0 0 0);
		}

	walls
		{
			type		symmetry;
		}
"proc.*"
{
    type            processor;
}
	
}

p/

boundaryField
{

	inlet
		{
        		type           zeroGradient;
		}

    	outlet
    		{
       			type           fixedValue;
			value		uniform 0;
    		}

	top
		{
			type		symmetry; 	//zeoGradient;
		}
	
	bottom
		{
			type		zeroGradient;
		}

	walls
		{
			type		symmetry; 	//zeoGradient;
		}

"proc.*"
{
    type            processor;
}

k/

internalField   uniform 3.375e-4; //1.5*I_t^2*U_m^2

boundaryField
{
    inlet
    {
        type            groovyBC;
        variables	(
			"U_m=0.3;"
			"h=0.3;"
			"z0=0.001;"
			"I_t=0.05;"
			"r=pos().z/z0;"
			"I=I_t*((log(h/z0))/(log(pos().z/z0)));"
			);
	valueExpression	"1.5*pow(I,2)*pow(U_m,2)";
			
    }
    outlet
    {
        type            zeroGradient;
    }
    top
    {
        type		symmetry;			//type           kqRWallFunction;
        						//value          uniform 3.375e-4;
    }
    bottom
    {
        type            kqRWallFunction;
        		value           uniform 3.375e-4;
    }
    walls
    {
        type		symmetry;			//type           kqRWallFunction;
        						//value           uniform 3.375e-4;
    }

"proc.*"
{
    type            processor;
}
}

epsilon /

internalField   uniform 4.851e-5;

boundaryField
{
    inlet
    {
        type            fixedValue;
        value           uniform 4.851e-5;
    }
    outlet
    {
        type            zeroGradient;
    }
    top
    {
        type		symmetry;		//type           epsilonWallFunction;
        					//value          uniform 4.851e-5;
    }
    bottom
    {
        type            epsilonWallFunction;
        		value           uniform 4.851e-5;
    }
    walls
    {
        type		symmetry;		//type           epsilonWallFunction;
        					//value          uniform 4.851e-5;
    }

"proc.*"
{
    type            processor;
}
}

fvSchemes

ddtSchemes
{
    default             steadyState;
}

gradSchemes
{
    default             Gauss linear;
}

divSchemes
{
    default             none;

    div(phi,U)          bounded Gauss upwind;
    div(phi,epsilon)    bounded Gauss upwind;
    div(phi,k)          bounded Gauss upwind;

    div((nuEff*dev2(T(grad(U)))))    Gauss linear;
}

laplacianSchemes
{
    default             Gauss linear limited corrected 0.33;
}

interpolationSchemes
{
    default             linear;
}

snGradSchemes
{
    default             limited corrected 0.33;
}

fvSolution

solvers
{
    p
    {
        solver           GAMG;
        tolerance        1e-6;
        relTol           0.1;
        smoother         GaussSeidel;
    }

    U
    {
        solver           smoothSolver;
        smoother         GaussSeidel;
        tolerance        1e-6;
        relTol           0.1;
        nSweeps          1;
    }

    k
    {
        solver           smoothSolver;
        smoother         GaussSeidel;
        tolerance        1e-6;
        relTol           0.1;
        nSweeps          1;
    }

    epsilon
    {
        solver           smoothSolver;
        smoother         GaussSeidel;
        tolerance        1e-6;
        relTol           0.1;
        nSweeps          1;
    }
}

SIMPLE
{
    nNonOrthogonalCorrectors 0;

    residualControl
    {
        p               1e-3;
        U               1e-4;
        "(k|epsilon)"   1e-4;
    }
}

relaxationFactors
{
    fields
    {
        p               0.3;
    }
    equations
    {
        U               0.7;
        k               0.7;
        epsilon         0.7;
    }
}

cache
{
    grad(U);
}

Thank you!!!