ForcingAxiSymmetric.cpp

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///////////////////////////////////////////////////////////////////////////////
//
// File: ForcingAxiSymmetric.cpp
//
// For more information, please see: http://www.nektar.info
//
// The MIT License
//
// Copyright (c) 2006 Division of Applied Mathematics, Brown University (USA),
// Department of Aeronautics, Imperial College London (UK), and Scientific
// Computing and Imaging Institute, University of Utah (USA).
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//
// Description: Forcing for axi-symmetric flow.
//
///////////////////////////////////////////////////////////////////////////////
 
#include <CompressibleFlowSolver/Forcing/ForcingAxiSymmetric.h>
 
using namespace std;
 
namespace Nektar
{
std::string ForcingAxiSymmetric::className =
    SolverUtils::GetForcingFactory().RegisterCreatorFunction(
        "AxiSymmetric", ForcingAxiSymmetric::create,
        "Forcing for axi-symmetric flow (around x=0)");
 
ForcingAxiSymmetric::ForcingAxiSymmetric(
    const LibUtilities::SessionReaderSharedPtr &pSession,
    const std::weak_ptr<SolverUtils::EquationSystem> &pEquation)
    : Forcing(pSession, pEquation)
{
}
 
void ForcingAxiSymmetric::v_InitObject(
    const Array<OneD, MultiRegions::ExpListSharedPtr> &pFields,
    const unsigned int &pNumForcingFields,
    [[maybe_unused]] const TiXmlElement *pForce)
{
    int spacedim = pFields[0]->GetGraph()->GetSpaceDimension();
    int nPoints  = pFields[0]->GetTotPoints();
 
    m_NumVariable = pNumForcingFields;
    m_varConv = MemoryManager<VariableConverter>::AllocateSharedPtr(m_session,
                                                                    spacedim);
 
    // Get coordinates
    Array<OneD, Array<OneD, NekDouble>> coords(3);
    for (int i = 0; i < 3; i++)
    {
        coords[i] = Array<OneD, NekDouble>(nPoints);
    }
    pFields[0]->GetCoords(coords[0], coords[1], coords[2]);
 
    // Calculate fac = -1/r if r!=0, fac = 0 if r == 0
    m_geomFactor = Array<OneD, NekDouble>(nPoints);
    for (int i = 0; i < nPoints; ++i)
    {
        if (coords[0][i] < NekConstants::kNekZeroTol)
        {
            m_geomFactor[i] = 0;
        }
        else
        {
            m_geomFactor[i] = -1.0 / coords[0][i];
        }
    }
 
    // Project m_geomFactor to solution space
    m_Forcing = Array<OneD, Array<OneD, NekDouble>>(m_NumVariable);
    for (int i = 0; i < m_NumVariable; ++i)
    {
        m_Forcing[i] = Array<OneD, NekDouble>(pFields[0]->GetTotPoints(), 0.0);
    }
}
 
void ForcingAxiSymmetric::v_Apply(
    const Array<OneD, MultiRegions::ExpListSharedPtr> &pFields,
    const Array<OneD, Array<OneD, NekDouble>> &inarray,
    Array<OneD, Array<OneD, NekDouble>> &outarray,
    [[maybe_unused]] const NekDouble &time)
{
    int nPoints = pFields[0]->GetTotPoints();
 
    // Get (E+p)
    Array<OneD, NekDouble> tmp(nPoints, 0.0);
    m_varConv->GetPressure(inarray, tmp);
    Vmath::Vadd(nPoints, tmp, 1, inarray[m_NumVariable - 1], 1, tmp, 1);
 
    // F-rho = -1/r *rhou
    Vmath::Vmul(nPoints, m_geomFactor, 1, inarray[1], 1, m_Forcing[0], 1);
 
    // F-rhou_r = -1/r *rhou_r * u_r and F-rhou_y = -1/r *rhou_y * u_r
    for (int i = 1; i < 3; ++i)
    {
        Vmath::Vmul(nPoints, inarray[1], 1, inarray[i], 1, m_Forcing[i], 1);
        Vmath::Vdiv(nPoints, m_Forcing[i], 1, inarray[0], 1, m_Forcing[i], 1);
        Vmath::Vmul(nPoints, m_Forcing[i], 1, m_geomFactor, 1, m_Forcing[i], 1);
    }
 
    // F-E = -1/r *(E+p)*u
    Vmath::Vmul(nPoints, inarray[1], 1, tmp, 1, m_Forcing[m_NumVariable - 1],
                1);
    Vmath::Vdiv(nPoints, m_Forcing[m_NumVariable - 1], 1, inarray[0], 1,
                m_Forcing[m_NumVariable - 1], 1);
    Vmath::Vmul(nPoints, m_Forcing[m_NumVariable - 1], 1, m_geomFactor, 1,
                m_Forcing[m_NumVariable - 1], 1);
 
    // Swirl
    if (m_NumVariable == 5)
    {
        // F-rhou_r -= (-1/r) * rho * u_theta * u_theta
        Vmath::Vmul(nPoints, inarray[3], 1, inarray[3], 1, tmp, 1);
        Vmath::Vdiv(nPoints, tmp, 1, inarray[0], 1, tmp, 1);
        Vmath::Vmul(nPoints, tmp, 1, m_geomFactor, 1, tmp, 1);
        Vmath::Vsub(nPoints, m_Forcing[1], 1, tmp, 1, m_Forcing[1], 1);
 
        // F-rhou_theta = 2 * (-1/r *rhou_theta * u_r)
        Vmath::Vmul(nPoints, inarray[1], 1, inarray[3], 1, m_Forcing[3], 1);
        Vmath::Vdiv(nPoints, m_Forcing[3], 1, inarray[0], 1, m_Forcing[3], 1);
        Vmath::Vmul(nPoints, m_Forcing[3], 1, m_geomFactor, 1, m_Forcing[3], 1);
        Vmath::Smul(nPoints, 2.0, m_Forcing[3], 1, m_Forcing[3], 1);
    }
 
    // Apply forcing
    for (int i = 0; i < m_NumVariable; i++)
    {
        Vmath::Vadd(nPoints, outarray[i], 1, m_Forcing[i], 1, outarray[i], 1);
    }
}
 
} // namespace Nektar