void prepareLattice(LBconverter<T> const* converter,
BlockStructure2D<T,DESCRIPTOR>& lattice,
Dynamics<T, DESCRIPTOR>& bulkDynamics,
OnLatticeBoundaryCondition2D<T,DESCRIPTOR>& bc ){
const int nx = lattice.getNx();
const int ny = lattice.getNy();
const T omega = converter->getOmega();
// link lattice with dynamics for collision step
lattice.defineDynamics(0,nx-1, 0,ny-1, &bulkDynamics);
// left boundary
bc.addVelocityBoundary0N( 0, 0, 1,ny-2, omega);
// right boundary
bc.addVelocityBoundary0P(nx-1,nx-1, 1,ny-2, omega);
// bottom boundary
bc.addVelocityBoundary1N( 1,nx-2, 0, 0, omega);
// top boundary
bc.addVelocityBoundary1P( 1,nx-2,ny-1,ny-1, omega);
// corners
bc.addExternalVelocityCornerNN( 0, 0, omega);
bc.addExternalVelocityCornerNP( 0,ny-1, omega);
bc.addExternalVelocityCornerPN(nx-1, 0, omega);
bc.addExternalVelocityCornerPP(nx-1,ny-1, omega);
}
void iniGeometry( BlockStructure2D<T, DESCRIPTOR>& lattice,
LBunits<T> const& converter,
Dynamics<T, DESCRIPTOR>& bulkDynamics,
OnLatticeBoundaryCondition2D<T,DESCRIPTOR>& boundaryCondition,
BoundaryType boundaryType )
{
int nx = converter.getNx();
int ny = converter.getNy();
T omega = converter.getOmega();
lattice.defineDynamics(0,nx-1, 0,ny-1, &bulkDynamics);
boundaryCondition.addVelocityBoundary1P(1,nx-2,ny-1,ny-1, omega);
boundaryCondition.addVelocityBoundary1N(1,nx-2, 0, 0, omega);
if (boundaryType==velocity) {
boundaryCondition.addVelocityBoundary0N(0,0, 1, ny-2, omega);
boundaryCondition.addVelocityBoundary0P(nx-1,nx-1, 1, ny-2, omega);
}
else {
boundaryCondition.addPressureBoundary0N(0,0, 1, ny-2, omega);
boundaryCondition.addPressureBoundary0P(nx-1,nx-1, 1, ny-2, omega);
}
boundaryCondition.addExternalVelocityCornerNN(0,0, omega);
boundaryCondition.addExternalVelocityCornerNP(0,ny-1, omega);
boundaryCondition.addExternalVelocityCornerPN(nx-1,0, omega);
boundaryCondition.addExternalVelocityCornerPP(nx-1,ny-1, omega);
for (int iX=0; iX<nx; ++iX) {
for (int iY=0; iY<ny; ++iY) {
T u[2] = {poiseuilleVelocity(iY, converter),0.};
T rho = (T)1 + poiseuillePressure(iX, converter) * DESCRIPTOR<T>::invCs2;
lattice.get(iX,iY).defineRhoU(rho, u);
lattice.get(iX,iY).iniEquilibrium(rho, u);
}
}
lattice.initialize();
}
void prepareLattice(LBconverter<T> const& converter,
BlockStructure2D<T, DESCRIPTOR>& lattice,
Dynamics<T, DESCRIPTOR>& bulkDynamics,
OnLatticeBoundaryCondition2D<T,DESCRIPTOR>& boundaryCondition ) {
int nx = lattice.getNx();
int ny = lattice.getNy();
T omega = converter.getOmega();
/// define lattice Dynamics
lattice.defineDynamics(0,nx-1, 0,ny-1, &bulkDynamics);
/// sets boundary
boundaryCondition.addVelocityBoundary1P(1,nx-2,ny-1,ny-1, omega);
boundaryCondition.addVelocityBoundary1N(1,nx-2, 0, 0, omega);
/// set Velocity
boundaryCondition.addExternalVelocityCornerNN(0,0, omega);
boundaryCondition.addExternalVelocityCornerNP(0,ny-1, omega);
boundaryCondition.addExternalVelocityCornerPN(nx-1,0, omega);
boundaryCondition.addExternalVelocityCornerPP(nx-1,ny-1, omega);
}
void iniGeometry( BlockStructure2D<T, DESCRIPTOR>& latticeOne,
BlockStructure2D<T, DESCRIPTOR>& latticeTwo,
Dynamics<T, DESCRIPTOR>& bulkDynamics1,
Dynamics<T, DESCRIPTOR>& bulkDynamics2,
Dynamics<T, DESCRIPTOR>& bounceBackRho0,
Dynamics<T, DESCRIPTOR>& bounceBackRho1,
T force
)
{
// The setup is: periodicity along horizontal direction, bounce-back on top
// and bottom. The upper half is initially filled with fluid 1 + random noise,
// and the lower half with fluid 2. Only fluid 1 experiences a forces,
// directed downwards.
T noise = 1.e-2;
int nx = latticeOne.getNx();
int ny = latticeOne.getNy();
latticeOne.defineDynamics(0,nx-1, 0,ny-1, &bulkDynamics1);
latticeTwo.defineDynamics(0,nx-1, 0,ny-1, &bulkDynamics2);
latticeOne.defineDynamics(0,nx-1, 0,0, &bounceBackRho0);
latticeTwo.defineDynamics(0,nx-1, 0,0, &bounceBackRho1);
latticeOne.defineDynamics(0,nx-1, ny-1,ny-1, &bounceBackRho1);
latticeTwo.defineDynamics(0,nx-1, ny-1,ny-1, &bounceBackRho0);
for (int iX=0; iX<nx; ++iX) {
for (int iY=0; iY<ny; ++iY) {
T f[2] = {0.,-force};
T zeroVelocity[2] = {0.,0.};
T noForce[2] = {0.,0.};
T rho1 = (T)1;
T rho2 = (T)1;
if (iY>ny/2) {
rho2 = 0.;
rho1 += (double)random()/(double)RAND_MAX * noise;
rho1 += force*DESCRIPTOR<T>::invCs2* ((T)ny - (T)iY - (T)ny/(T)2);
}
else {
rho1 = 0.;
}
Cell<T,DESCRIPTOR>& cell1 = latticeOne.get(iX,iY);
cell1.defineRhoU(rho1, zeroVelocity);
cell1.iniEquilibrium(rho1, zeroVelocity);
cell1.defineExternalField (
DESCRIPTOR<T>::ExternalField::forceBeginsAt,
DESCRIPTOR<T>::ExternalField::sizeOfForce, f );
Cell<T,DESCRIPTOR>& cell2 = latticeTwo.get(iX,iY);
cell2.defineRhoU(rho2, zeroVelocity);
cell2.iniEquilibrium(rho2, zeroVelocity);
cell2.defineExternalField (
DESCRIPTOR<T>::ExternalField::forceBeginsAt,
DESCRIPTOR<T>::ExternalField::sizeOfForce, noForce );
}
}
latticeOne.initialize();
latticeTwo.initialize();
}
