[openfoammaofnepo]

Dear All,

For round jet flow problems, I know how to build the 2D mesh from blockmesh for the axisymmetric geometry. I should use the wedge for that.

However, for the same problems, if I would like to generate the 3D hexahedral mesh for the cylinderical gemoetry of the jet flow domain, how can I do that? Could anybody give me some hints for that? The computational domain is cylinder, with the boundries of jet exit, coflow inlet, side boundaries and outlet.

Thank you so much for your help.
OFFO

[Tobi]

Hi,

there are more ways to do this. The easiest (for you) is to use the 2d wedge mesh and extrude it by 360degree using extrudeMesh utility (:

[openfoammaofnepo]

Dear Tobi,

Thank you for your reply. I have generated a wedge with 5 degree and the boundaries of front and back. These two boundaries saddle at y-axis (x is the symmetric axis) with 2.5 degree and -2.5 degree. So now I would like to extrude the front and back boundary along the outward normal vector with 20 degree. Finally I will get a 45 degree section of cylinder. I tried extrudeMesh utility and the following dictionary. BUt there are some problems about:

Testing:"../testcase/system/fvSchemes"
#0  Foam::error::printStack(Foam::Ostream&) at ??:?
#1  Foam::sigFpe::sigHandler(int) at ??:?
#2   in "/lib64/libc.so.6"
#3   at wedgePolyPatch.C:?
#4  Foam::wedgePolyPatch::wedgePolyPatch(Foam::wedgePolyPatch const&, Foam::polyBoundaryMesh const&, int, int, int) at ??:?
#5  Foam::wedgePolyPatch::clone(Foam::polyBoundaryMesh const&, int, int, int) const at ??:?
#6  Foam::polyTopoChange::makeMesh(Foam::autoPtr<Foam::fvMesh>&, Foam::IOobject const&, Foam::polyMesh const&, bool, bool, bool) at ??:?
#7
 at ??:?
#8  __libc_start_main in "/lib64/libc.so.6"

The dictionary I am useing is as following. Could you please tell me what I should I modify further?

//constructFrom mesh;
constructFrom patch;
//constructFrom surface;

// If construct from patch/mesh:
sourceCase "../testcase";
sourcePatches (front);
// If construct from patch: patch to use for back (can be same as sourcePatch)
exposedPatchName front;
// If construct from surface:
surface "movingWall.stl";

// Flip surface normals before usage. Valid only for extrude from surface or
// patch.
flipNormals false;

//- Linear extrusion in point-normal direction
//extrudeModel        linearNormal;

//- Linear extrusion in specified direction
//extrudeModel        linearDirection;

//- Wedge extrusion. If nLayers is 1 assumes symmetry around plane.
extrudeModel        wedge;

//- Extrudes into sphere around (0 0 0)
//extrudeModel        linearRadial;

//- Extrudes into sphere around (0 0 0) with specified radii
//extrudeModel        radial;

//- Extrudes into sphere with grading according to pressure (atmospherics)
//extrudeModel        sigmaRadial;

nLayers             10;

expansionRatio      1.0;    //0.9;

wedgeCoeffs
{
    axisPt      (0 0 0);
    axis        (1 0 0);
    angle       20;  // For nLayers=1 assume symmetry so angle/2 on each side
}

linearNormalCoeffs
{
    thickness       0.05;
}

linearDirectionCoeffs
{
    direction       (0 1 0);
    thickness       0.05;
}

linearRadialCoeffs
{
    R               0.1;
    // Optional inner radius
    Rsurface        0.01;
}

radialCoeffs
{
    // Radii specified through interpolation table
    R               table ((0 0.01)(3 0.03)(10 0.1));
}


sigmaRadialCoeffs
{
    RTbyg           1;
    pRef            1;
    pStrat          1;
}

// Do front and back need to be merged? Usually only makes sense for 360
// degree wedges.
mergeFaces false;   //true;

// Merge small edges. Fraction of bounding box.
mergeTol 0;