# Problems with applying thoms formula

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 February 15, 2022, 02:54 Problems with applying thoms formula #1 New Member   Patryk Join Date: Dec 2021 Posts: 5 Rep Power: 2 Hello everyone. I'm working on a solver that solves vorticiy-stream function equation. One of the things I wanted to apply, to one of my case, was 0 velocity at the boundary. To achieve that, I wasn't simply applying 0 velocity at the boundary, since I'm not using primitive variables. My idea was to, make such boundary condition that will create vortex itself, that in result of "mixing" will create a 0-velocity slice near the wall. So this is a code of my Thoms formula, atleast this is what i think its called. Code: const fvPatch& boundaryPatch = patch(); // this patch // make a reference to the mesh so that I can access variables const fvMesh& mesh = patch().boundaryMesh().mesh(); const volScalarField& psi = db().lookupObject("psi"); const volScalarField& OM = db().lookupObject("OM"); label inletPatchID = mesh.boundaryMesh().findPatchID("bottom"); label inletPatchID2 = mesh.boundaryMesh().findPatchID("left"); // Get reference to boundary field value const scalarField& psib = psi.boundaryField()[inletPatchID]; const scalarField& OMb = OM.boundaryField()[inletPatchID]; // get coordinate for cell centres const fvPatchVectorField& centre = mesh.C().boundaryField()[inletPatchID]; const fvPatchVectorField& centreleft = mesh.C().boundaryField()[inletPatchID2]; //const fvPatchVectorField& centre = mesh.C().boundaryField()[inletPatchID]; //area of patch scalarField areasc = mesh.magSf().boundaryField()[inletPatchID]; scalarField OMwall = OMb; scalar area = sum(areasc); scalar d; // THOMAS FORMULA forAll (psib, cellI) { d = mag(mesh.C()[cellI].component(vector::Y) - centre[cellI].component(vector::Y)); OMwall [cellI] = -2.0*psib[cellI]/(d*d); } Info << (OMwall); operator==(OMwall); Generally all i want to achieve is the vorticity at the wall that will be equal to: =

 Tags boundary condition, cfd, vorticity