CodedFixedValue边界赋值后，noslip壁面变为滑移边界？

[veen]

今天在做模拟的时候发现，对入口进行CodedFixedValue边界赋值后，noslip壁面的速度不为0，换成FixedValue边界后又正常了，这是为什么呢？
Uboundary condition

FoamFile
{
    version     2.0;
    format      ascii;
    class       volVectorField;
    object      U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 1 -1 0 0 0 0];

internalField   uniform (10 0 0);

boundaryField
{
    inlet
    {
        type            codedFixedValue;
        value           uniform (10 0 0);
        name            codeinlet;
        code            #{
            const fvPatch& boundaryPatch = this->patch();

            vectorField U = boundaryPatch.Cf();
            vectorField u = boundaryPatch.Cf();
            
            scalar zstar = 0.003;
            scalar kappa = 0.41;
            scalar ustar = 0.726;
            scalar ubar  = 10;

            forAll(boundaryPatch, faceI)
            {
            //spatial coordinates, type: scalar
            scalar y = boundaryPatch.Cf()[faceI].y();
                        
            U[faceI] = vector((ustar/kappa)*log(1+y/zstar), 0, 0);
            u[faceI] = 0.1*ubar*exp(-0.5*y)*vector(rand() % 2 - 1, rand() % 2 - 1, rand() % 2 - 1);
            U[faceI] = U[faceI]+u[faceI];
            if (U[faceI].x() < 0)
            {
                U[faceI].x() = -U[faceI].x();
            }
            }
            
            operator==(U+u);
        #};
    }

    outlet
    {
        type            zeroGradient;
    }

    land
    {
        type            noSlip;
    }

    symmetry
    {
        type            slip;
    }
}

这是计算得到的流场

案例文件在这：case.zip

[veen]

@veen 破案了，应该是paraview读取case的问题openfoam-post-processing