ForcingBody.cpp

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///////////////////////////////////////////////////////////////////////////////
//
// File: ForcingBody.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: Body forcing
//
///////////////////////////////////////////////////////////////////////////////
 
#include <MultiRegions/ExpList.h>
#include <SolverUtils/Forcing/ForcingBody.h>
 
using namespace std;
 
namespace Nektar
{
namespace SolverUtils
{
 
std::string ForcingBody::classNameBody =
    GetForcingFactory().RegisterCreatorFunction("Body", ForcingBody::create,
                                                "Body Forcing");
std::string ForcingBody::classNameField =
    GetForcingFactory().RegisterCreatorFunction("Field", ForcingBody::create,
                                                "Field Forcing");
 
ForcingBody::ForcingBody(const LibUtilities::SessionReaderSharedPtr &pSession,
                         const std::weak_ptr<EquationSystem> &pEquation)
    : Forcing(pSession, pEquation), m_hasTimeFcnScaling(false)
{
}
 
void ForcingBody::v_InitObject(
    const Array<OneD, MultiRegions::ExpListSharedPtr> &pFields,
    const unsigned int &pNumForcingFields, const TiXmlElement *pForce)
{
    m_NumVariable = pNumForcingFields;
 
    const TiXmlElement *funcNameElmt = pForce->FirstChildElement("BODYFORCE");
    if (!funcNameElmt)
    {
        funcNameElmt = pForce->FirstChildElement("FIELDFORCE");
 
        ASSERTL0(funcNameElmt,
                 "Requires BODYFORCE or FIELDFORCE tag "
                 "specifying function name which prescribes body force.");
    }
 
    m_funcName = funcNameElmt->GetText();
    ASSERTL0(m_session->DefinesFunction(m_funcName),
             "Function '" + m_funcName + "' not defined.");
 
    bool singleMode, halfMode;
    m_session->MatchSolverInfo("ModeType", "SingleMode", singleMode, false);
    m_session->MatchSolverInfo("ModeType", "HalfMode", halfMode, false);
    bool homogeneous = pFields[0]->GetExpType() == MultiRegions::e3DH1D ||
                       pFields[0]->GetExpType() == MultiRegions::e3DH2D;
    m_transform = (singleMode || halfMode || homogeneous);
 
    // Time function is optional
    funcNameElmt = pForce->FirstChildElement("BODYFORCETIMEFCN");
    if (!funcNameElmt)
    {
        funcNameElmt = pForce->FirstChildElement("FIELDFORCETIMEFCN");
    }
 
    // Load time function if specified
    if (funcNameElmt)
    {
        std::string funcNameTime = funcNameElmt->GetText();
 
        ASSERTL0(!funcNameTime.empty(),
                 "Expression must be given in BODYFORCETIMEFCN or "
                 "FIELDFORCETIMEFCN.");
 
        m_session->SubstituteExpressions(funcNameTime);
        m_timeFcnEqn = MemoryManager<LibUtilities::Equation>::AllocateSharedPtr(
            m_session->GetInterpreter(), funcNameTime);
 
        m_hasTimeFcnScaling = true;
    }
 
    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);
    }
 
    Array<OneD, Array<OneD, NekDouble>> tmp(pFields.size());
    for (int i = 0; i < m_NumVariable; ++i)
    {
        tmp[i] = pFields[i]->GetPhys();
    }
 
    Update(pFields, tmp, 0.0);
}
 
void ForcingBody::Update(
    const Array<OneD, MultiRegions::ExpListSharedPtr> &pFields,
    const Array<OneD, Array<OneD, NekDouble>> &inarray, const NekDouble &time)
{
    for (int i = 0; i < m_NumVariable; ++i)
    {
        if (LibUtilities::eFunctionTypeExpression ==
            m_session->GetFunctionType(m_funcName, m_session->GetVariable(i)))
        {
            LibUtilities::EquationSharedPtr eqn =
                m_session->GetFunction(m_funcName, m_session->GetVariable(i));
            if (!boost::iequals(eqn->GetVlist(), "x y z t"))
            {
                // Coupled forcing
                int nq = pFields[0]->GetNpoints();
                Array<OneD, NekDouble> xc(nq), yc(nq), zc(nq), t(nq, time);
                std::string varstr                                  = "x y z";
                std::vector<Array<OneD, const NekDouble>> fielddata = {xc, yc,
                                                                       zc, t};
 
                for (int j = 0; j < m_NumVariable; ++j)
                {
                    varstr += " " + m_session->GetVariable(j);
                    fielddata.push_back(inarray[j]);
                }
 
                // Evaluate function
                m_session->GetFunction(m_funcName, m_session->GetVariable(i))
                    ->Evaluate(fielddata, m_Forcing[i]);
                continue;
            }
        }
        std::string s_FieldStr = m_session->GetVariable(i);
        ASSERTL0(m_session->DefinesFunction(m_funcName, s_FieldStr),
                 "Variable '" + s_FieldStr + "' not defined.");
        GetFunction(pFields, m_session, m_funcName, true)
            ->Evaluate(s_FieldStr, m_Forcing[i], time);
    }
 
    // If singleMode or halfMode, transform the forcing term to be in
    // physical space in the plane, but Fourier space in the homogeneous
    // direction
    if (m_transform)
    {
        for (int i = 0; i < m_NumVariable; ++i)
        {
            pFields[0]->HomogeneousFwdTrans(m_Forcing[i], m_Forcing[i]);
        }
    }
}
 
void ForcingBody::v_Apply(
    const Array<OneD, MultiRegions::ExpListSharedPtr> &fields,
    const Array<OneD, Array<OneD, NekDouble>> &inarray,
    Array<OneD, Array<OneD, NekDouble>> &outarray, const NekDouble &time)
{
    if (m_hasTimeFcnScaling)
    {
        Array<OneD, NekDouble> TimeFcn(1);
 
        for (int i = 0; i < m_NumVariable; i++)
        {
            EvaluateTimeFunction(time, m_timeFcnEqn, TimeFcn);
 
            Vmath::Svtvp(outarray[i].size(), TimeFcn[0], m_Forcing[i], 1,
                         outarray[i], 1, outarray[i], 1);
        }
    }
    else
    {
        Update(fields, inarray, time);
 
        for (int i = 0; i < m_NumVariable; i++)
        {
            Vmath::Vadd(outarray[i].size(), outarray[i], 1, m_Forcing[i], 1,
                        outarray[i], 1);
        }
    }
}
 
void ForcingBody::v_ApplyCoeff(
    const Array<OneD, MultiRegions::ExpListSharedPtr> &fields,
    const Array<OneD, Array<OneD, NekDouble>> &inarray,
    Array<OneD, Array<OneD, NekDouble>> &outarray, const NekDouble &time)
{
    int ncoeff = outarray[m_NumVariable - 1].size();
    Array<OneD, NekDouble> tmp(ncoeff, 0.0);
 
    if (m_hasTimeFcnScaling)
    {
        Array<OneD, NekDouble> TimeFcn(1);
 
        for (int i = 0; i < m_NumVariable; ++i)
        {
            EvaluateTimeFunction(time, m_timeFcnEqn, TimeFcn);
 
            fields[i]->FwdTrans(m_Forcing[i], tmp);
 
            Vmath::Svtvp(ncoeff, TimeFcn[0], tmp, 1, outarray[i], 1,
                         outarray[i], 1);
        }
    }
    else
    {
        Update(fields, inarray, time);
 
        for (int i = 0; i < m_NumVariable; ++i)
        {
            fields[i]->FwdTrans(m_Forcing[i], tmp);
 
            Vmath::Vadd(ncoeff, outarray[i], 1, tmp, 1, outarray[i], 1);
        }
    }
}
 
} // namespace SolverUtils
} // namespace Nektar