ImmersedBoundary2dArrays.cpp

 
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*/
 
#include "ImmersedBoundary2dArrays.hpp"
#include <assert.h>
#include "Exception.hpp"
 
template<unsigned DIM>
ImmersedBoundary2dArrays<DIM>::ImmersedBoundary2dArrays(ImmersedBoundaryMesh<DIM,DIM>* pMesh, double dt, double reynoldsNumber, bool activeSources)
    : mpMesh(pMesh),
      mActiveSources(activeSources)
{
    unsigned num_gridpts_x = mpMesh->GetNumGridPtsX();
    unsigned num_gridpts_y = mpMesh->GetNumGridPtsY();
 
    // We require an even number of grid points
    assert(num_gridpts_y % 2 == 0);
 
    /*
     * Resize the grids.  All complex grids are half-sized in the y-coordinate due to redundancy inherent in the
     * fast-Fourier method for solving Navier-Stokes.
     */
    unsigned reduced_y = 1 + (num_gridpts_y/2);
 
    // Resize real arrays to be num X by num Y
    mForceGrids.resize(extents[2][num_gridpts_x][num_gridpts_y]);
 
    mRightHandSideGrids.resize(extents[3][num_gridpts_x][num_gridpts_y]);
 
    // The source gradient grids are only needed when fluid sources are present.  Otherwise, we need do nothing
    if(mActiveSources)
    {
        mSourceGradientGrids.resize(extents[2][num_gridpts_x][num_gridpts_y]);
    }
 
    // Resize Fourier-domain arrays
    // There are three such FourierGrid arrays if sources are active
    mOperator1.resize(extents[num_gridpts_x][reduced_y]);
    mOperator2.resize(extents[num_gridpts_x][reduced_y]);
    mFourierGrids.resize(extents[2 + (int)mActiveSources][num_gridpts_x][reduced_y]);
    mPressureGrid.resize(extents[num_gridpts_x][reduced_y]);
 
    mSin2x.resize(num_gridpts_x);
    mSin2y.resize(reduced_y);
 
    /*
     * There are several constants used in the Fourier domain as part of the Navier-Stokes solution which are constant
     * once grid sizes are known. We pre-calculate these to eliminate re-calculation at every time step.
     */
    double x_spacing = 1.0 / (double) num_gridpts_x;
    double y_spacing = 1.0 / (double) num_gridpts_y;
 
    for (unsigned x = 0; x < num_gridpts_x; x++)
    {
        mSin2x[x] = sin(2 * M_PI * (double) x * x_spacing);
    }
 
    for (unsigned y = 0; y < reduced_y; y++)
    {
        mSin2y[y] = sin(2 * M_PI * (double) y * y_spacing);
    }
 
    for (unsigned x = 0; x < num_gridpts_x; x++)
    {
        for (unsigned y = 0; y < reduced_y; y++)
        {
            mOperator1[x][y] = (mSin2x[x] * mSin2x[x] / (x_spacing * x_spacing)) + (mSin2y[y] * mSin2y[y] / (y_spacing * y_spacing));
            mOperator1[x][y] *= dt / reynoldsNumber;
 
            double sin_x = sin(M_PI * (double) x * x_spacing);
            double sin_y = sin(M_PI * (double) y * y_spacing);
 
            mOperator2[x][y] = (sin_x * sin_x / (x_spacing * x_spacing)) + (sin_y * sin_y / (y_spacing * y_spacing));
            mOperator2[x][y] *= 4.0 * dt / reynoldsNumber;
            mOperator2[x][y] += 1.0;
        }
    }
}
 
template<unsigned DIM>
ImmersedBoundary2dArrays<DIM>::~ImmersedBoundary2dArrays()
{
}
 
template<unsigned DIM>
multi_array<double, 3>& ImmersedBoundary2dArrays<DIM>::rGetModifiableForceGrids()
{
    return mForceGrids;
}
 
template<unsigned DIM>
multi_array<double, 3>& ImmersedBoundary2dArrays<DIM>::rGetModifiableRightHandSideGrids()
{
    return mRightHandSideGrids;
}
 
template<unsigned DIM>
multi_array<double, 3>& ImmersedBoundary2dArrays<DIM>::rGetModifiableSourceGradientGrids()
{
    return mSourceGradientGrids;
}
 
template<unsigned DIM>
multi_array<std::complex<double>, 3>& ImmersedBoundary2dArrays<DIM>::rGetModifiableFourierGrids()
{
    return mFourierGrids;
}
 
template<unsigned DIM>
multi_array<std::complex<double>, 2>& ImmersedBoundary2dArrays<DIM>::rGetModifiablePressureGrid()
{
    return mPressureGrid;
}
 
template<unsigned DIM>
const multi_array<double, 2>& ImmersedBoundary2dArrays<DIM>::rGetOperator1() const
{
    return mOperator1;
}
 
template<unsigned DIM>
const multi_array<double, 2>& ImmersedBoundary2dArrays<DIM>::rGetOperator2() const
{
    return mOperator2;
}
 
template<unsigned DIM>
const std::vector<double>& ImmersedBoundary2dArrays<DIM>::rGetSin2x() const
{
    return mSin2x;
}
 
template<unsigned DIM>
const std::vector<double>& ImmersedBoundary2dArrays<DIM>::rGetSin2y() const
{
    return mSin2y;
}
 
template<unsigned DIM>
ImmersedBoundaryMesh<DIM,DIM>* ImmersedBoundary2dArrays<DIM>::GetMesh()
{
    return mpMesh;
}
 
template<unsigned DIM>
bool ImmersedBoundary2dArrays<DIM>::HasActiveSources()
{
    return mActiveSources;
}
 
// Explicit instantiation
template class ImmersedBoundary2dArrays<1>;
template class ImmersedBoundary2dArrays<2>;
template class ImmersedBoundary2dArrays<3>;