Corner Node Boundary Conditions

Lattice Boltzmann Method LBM: Algorithms
#1

I am looking for a bit of input/error checking of my code I have included just the relevant portions of code to the BCs and calling them from main.

I am looking to do the following:

CBBBBBBBBBBBBBBBBBBBBBBBBBc
X ---------------------------------------------O
X ---------------------------------------------O
X ---------------------------------------------O
X ---------------------------------------------O
CBBBBBBBBBBBBBBBBBBBBBBBBBc

c-corner node, boundary::outflow
C-corner node, boundary::freeslip
X- inlet with defined rho and vel [Velocity BC]
O- outlet with rho defined [Pressure BC]
B- defined density bounce back [Contact angle (sort of)]

So this setup works with out the following lines:



    //Defines free slip at inlet corners
    boundaryCondition.addExternalVelocityCornerPP( 0, 0, lattice, boundary::freeslip );
    boundaryCondition.addExternalVelocityCornerPN( 0, ny-1, lattice, boundary::freeslip );

    //Defines free slip at outlet corners
    boundaryCondition.addExternalVelocityCornerNP( nx-1, 0, lattice, boundary::outflow );
    boundaryCondition.addExternalVelocityCornerNN( nx-1, ny-1, lattice, boundary::outflow );



void BCSetup( MultiBlockLattice2D<T,DESCRIPTOR>& lattice,
                   OnLatticeBoundaryCondition2D<T,DESCRIPTOR>& boundaryCondition )
{
    const plint gap = 1;
    Box2D inlet(0,0, 1, ny-2);
    Box2D outlet(nx-1,nx-1, 1, ny-2);
    Box2D bottom(0,nx-1, 0,0);
    Box2D top(0,nx-1, ny-1,ny-1);

    //Defines interaction density at boundary for the bounceback collision
    defineDynamics(lattice, bottom, new BounceBack<T, DESCRIPTOR>(solidRhoL) );
    defineDynamics(lattice, top, new BounceBack<T, DESCRIPTOR>(solidRhoL) );

    //
    boundaryCondition.setVelocityConditionOnBlockBoundaries (lattice, inlet );
    setBoundaryVelocity(lattice, inlet, inlet_vel);

    //Sets density everywhere to RhoAll
    setBoundaryDensity ( lattice, lattice.getBoundingBox(), RhoAll);
    //sets the density just at the outlet to DeltaRho (establishing the parameter needed for the pressure bc) 
    boundaryCondition.setPressureConditionOnBlockBoundaries (lattice, outlet );
    setBoundaryDensity ( lattice, outlet, DeltaRho );

    //Defines free slip at inlet corners
    boundaryCondition.addExternalVelocityCornerPP( 0, 0, lattice, boundary::freeslip );
    boundaryCondition.addExternalVelocityCornerPN( 0, ny-1, lattice, boundary::freeslip );

    //Defines free slip at outlet corners
    boundaryCondition.addExternalVelocityCornerNP( nx-1, 0, lattice, boundary::outflow );
    boundaryCondition.addExternalVelocityCornerNN( nx-1, ny-1, lattice, boundary::outflow );

}

int main(int argc, char *argv[])
{

    MultiBlockLattice2D<T, DESCRIPTOR> lattice (
            nx,ny, new ExternalMomentBGKdynamics<T, DESCRIPTOR>(omega));
    OnLatticeBoundaryCondition2D<T,DESCRIPTOR>*
        boundaryCondition = createInamuroBoundaryCondition2D<T,DESCRIPTOR>();
  
    BCSetup(lattice, *boundaryCondition);

    plint processorLevel = 1;
    integrateProcessingFunctional (
            new ShanChenSingleComponentProcessor2D<T,DESCRIPTOR> (
                G, new interparticlePotential::PsiShanChen94<T>(psi0,rho0) ),
            lattice.getBoundingBox(), lattice, processorLevel );

    lattice.initialize();

    for (int iT=0; iT<maxIter; ++iT) {
        lattice.collideAndStream();
    }
}

So my question is how to implement these corner nodes correctly?

Secondly am I implementing the other BCs the way I think I am?

~Thank you!