void VelocityStencil::apply ( FlowField & flowField, int i, int j, int k ){
const FLOAT dt = _parameters.timestep.dt;
const int obstacle = flowField.getFlags().getValue(i, j, k);
VectorField & velocity = flowField.getVelocity();
if ((obstacle & OBSTACLE_SELF) == 0) {
if ((obstacle & OBSTACLE_RIGHT) == 0) {
const FLOAT dx = 0.5*(_parameters.meshsize->getDx(i,j,k)+_parameters.meshsize->getDx(i+1,j,k));
velocity.getVector(i,j,k)[0] = flowField.getFGH().getVector(i,j,k)[0] - dt/dx *
(flowField.getPressure().getScalar(i+1,j,k) - flowField.getPressure().getScalar(i,j,k));
} else {
velocity.getVector(i, j, k)[0] = 0.0;
}
if ((obstacle & OBSTACLE_TOP) == 0) {
const FLOAT dy = 0.5*(_parameters.meshsize->getDy(i,j,k)+_parameters.meshsize->getDy(i,j+1,k));
velocity.getVector(i,j,k)[1] = flowField.getFGH().getVector(i,j,k)[1] - dt/dy *
(flowField.getPressure().getScalar(i,j+1,k) - flowField.getPressure().getScalar(i,j,k));
} else {
velocity.getVector(i, j, k)[1] = 0.0;
}
if ((obstacle & OBSTACLE_BACK) == 0) {
const FLOAT dz = 0.5*(_parameters.meshsize->getDz(i,j,k)+_parameters.meshsize->getDz(i,j,k+1));
velocity.getVector(i,j,k)[2] = flowField.getFGH().getVector(i,j,k)[2] - dt/dz *
(flowField.getPressure().getScalar(i,j,k+1) - flowField.getPressure().getScalar(i,j,k));
} else {
velocity.getVector(i, j, k)[2] = 0.0;
}
}
}
void VelocityStencil::apply ( FlowField & flowField, int i, int j ){
const FLOAT dt = _parameters.timestep.dt;
const int obstacle = flowField.getFlags().getValue(i, j);
VectorField & velocity = flowField.getVelocity();
if ((obstacle & OBSTACLE_SELF) == 0){ // If this is a fluid cell
if ((obstacle & OBSTACLE_RIGHT) == 0){ // Check whether the neighbor is also fluid
// we require a spatial finite difference expression for the pressure gradient, evaluated
// at the location of the u-component. We therefore compute the distance of neighbouring
// pressure values (dx) and use this as sort-of central difference expression. This will
// yield second-order accuracy for uniform meshsizes.
const FLOAT dx = 0.5*(_parameters.meshsize->getDx(i,j)+_parameters.meshsize->getDx(i+1,j));
velocity.getVector(i,j)[0] = flowField.getFGH().getVector(i,j)[0] - dt/dx *
(flowField.getPressure().getScalar(i+1,j) - flowField.getPressure().getScalar(i,j));
} else { // Otherwise, set to zero
velocity.getVector(i,j)[0] = 0;
} // Note that we only set one direction per cell. The neighbor at the left is
// responsible for the other side
if ((obstacle & OBSTACLE_TOP) == 0){
const FLOAT dy = 0.5*(_parameters.meshsize->getDy(i,j)+_parameters.meshsize->getDy(i,j+1));
velocity.getVector(i,j)[1] = flowField.getFGH().getVector(i,j)[1] - dt/dy *
(flowField.getPressure().getScalar(i,j+1) - flowField.getPressure().getScalar(i,j));
} else {
velocity.getVector(i,j)[1] = 0;
}
}
}
void VTKStencil:: apply ( FlowField & flowField, int i, int j, int k ){
if (i==1 || j==1 || k==1){return;}
int flag_value=flowField.getFlags().getValue(i,j,k);
FLOAT velocity[3];
FLOAT pressure;
flowField.getPressureAndVelocity(pressure,velocity,i,j,k);
if (flag_value & OBSTACLE_SELF){
if(output_flag == 0){
*(this->_outputFile)<<"0.0"<<std::endl;
}else{
*(this->_outputFile)<<"0.0 0.0 0.0"<<std::endl;
}
}else{
if(output_flag == 0){
*(this->_outputFile)<< pressure <<std::endl;
}else{
*(this->_outputFile)<< velocity[0] << " " << velocity[1] << " " << velocity[2] <<std::endl;
} }
return ;
}