CompressibleSolver.cpp

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///////////////////////////////////////////////////////////////////////////////
//
// File: CompressibleSolver.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: Compressible Riemann solver.
//
///////////////////////////////////////////////////////////////////////////////
 
#include "CompressibleSolver.h"
#include <boost/algorithm/string/predicate.hpp>
 
namespace Nektar
{
 
CompressibleSolver::CompressibleSolver(
    const LibUtilities::SessionReaderSharedPtr &pSession)
    : RiemannSolver(pSession), m_pointSolve(true)
{
    m_requiresRotation = true;
 
    // Create equation of state object
    std::string eosType;
    pSession->LoadSolverInfo("EquationOfState", eosType, "IdealGas");
    m_eos = GetEquationOfStateFactory().CreateInstance(eosType, pSession);
    // Check if using ideal gas
    m_idealGas = boost::iequals(eosType, "IdealGas");
}
 
CompressibleSolver::CompressibleSolver()
    : RiemannSolver(), m_pointSolve(true), m_idealGas(true)
{
    m_requiresRotation = true;
}
 
/**
 *
 */
void CompressibleSolver::v_Solve(
    const int nDim, const Array<OneD, const Array<OneD, NekDouble>> &Fwd,
    const Array<OneD, const Array<OneD, NekDouble>> &Bwd,
    Array<OneD, Array<OneD, NekDouble>> &flux)
{
    if (m_pointSolve)
    {
        size_t expDim = nDim;
        NekDouble rhouf{}, rhovf{};
 
        if (expDim == 1)
        {
            for (size_t i = 0; i < Fwd[0].size(); ++i)
            {
                v_PointSolve(Fwd[0][i], Fwd[1][i], 0.0, 0.0, Fwd[2][i],
                             Bwd[0][i], Bwd[1][i], 0.0, 0.0, Bwd[2][i],
                             flux[0][i], flux[1][i], rhouf, rhovf, flux[2][i]);
            }
        }
        else if (expDim == 2)
        {
            for (size_t i = 0; i < Fwd[0].size(); ++i)
            {
                v_PointSolve(Fwd[0][i], Fwd[1][i], Fwd[2][i], 0.0, Fwd[3][i],
                             Bwd[0][i], Bwd[1][i], Bwd[2][i], 0.0, Bwd[3][i],
                             flux[0][i], flux[1][i], flux[2][i], rhovf,
                             flux[3][i]);
            }
        }
        else if (expDim == 3)
        {
            for (size_t i = 0; i < Fwd[0].size(); ++i)
            {
                v_PointSolve(Fwd[0][i], Fwd[1][i], Fwd[2][i], Fwd[3][i],
                             Fwd[4][i], Bwd[0][i], Bwd[1][i], Bwd[2][i],
                             Bwd[3][i], Bwd[4][i], flux[0][i], flux[1][i],
                             flux[2][i], flux[3][i], flux[4][i]);
            }
        }
    }
    else
    {
        v_ArraySolve(Fwd, Bwd, flux);
    }
}
 
/**
 *
 */
NekDouble CompressibleSolver::GetRoeSoundSpeed(
    NekDouble rhoL, NekDouble pL, NekDouble eL, [[maybe_unused]] NekDouble HL,
    [[maybe_unused]] NekDouble srL, NekDouble rhoR, NekDouble pR, NekDouble eR,
    [[maybe_unused]] NekDouble HR, [[maybe_unused]] NekDouble srR,
    NekDouble HRoe, NekDouble URoe2, [[maybe_unused]] NekDouble srLR)
{
    static NekDouble gamma = m_params["gamma"]();
    NekDouble cRoe;
    if (m_idealGas)
    {
        cRoe = sqrt((gamma - 1.0) * (HRoe - 0.5 * URoe2));
    }
    else
    {
        // Calculate static enthalpy of left and right states
        NekDouble hL = eL + pL / rhoL;
        NekDouble hR = eR + pR / rhoR;
 
        // Get partial derivatives of P(rho,e)
        NekDouble dpdeL   = m_eos->GetDPDe_rho(rhoL, eL);
        NekDouble dpdeR   = m_eos->GetDPDe_rho(rhoR, eR);
        NekDouble dpdrhoL = m_eos->GetDPDrho_e(rhoL, eL);
        NekDouble dpdrhoR = m_eos->GetDPDrho_e(rhoR, eR);
 
        // Evaluate chi and kappa parameters
        NekDouble chiL   = dpdrhoL - eL / rhoL * dpdeL;
        NekDouble kappaL = dpdeL / rhoL;
        NekDouble chiR   = dpdrhoR - eR / rhoR * dpdeR;
        NekDouble kappaR = dpdeR / rhoR;
 
        //
        // Calculate interface speed of sound using procedure from
        //    Vinokur, M.; Montagné, J.-L. "Generalized Flux-Vector
        //    Splitting and Roe Average for an Equilibrium Real Gas",
        //    JCP (1990).
        //
 
        // Calculate averages
        NekDouble avgChi    = 0.5 * (chiL + chiR);
        NekDouble avgKappa  = 0.5 * (kappaL + kappaR);
        NekDouble avgKappaH = 0.5 * (kappaL * hL + kappaR * hR);
 
        // Calculate jumps
        NekDouble deltaP    = pR - pL;
        NekDouble deltaRho  = rhoR - rhoL;
        NekDouble deltaRhoe = rhoR * eR - rhoL * eL;
 
        // Evaluate dP: equation (64) from Vinokur-Montagné
        NekDouble dP = deltaP - avgChi * deltaRho - avgKappa * deltaRhoe;
        // s (eq 66)
        NekDouble s = avgChi + avgKappaH;
        // D (eq 65)
        NekDouble D = (s * deltaRho) * (s * deltaRho) + deltaP * deltaP;
        // chiRoe and kappaRoe (eq 66)
        NekDouble chiRoe, kappaRoe;
        NekDouble fac = D - deltaP * deltaRho;
        if (std::abs(fac) > NekConstants::kNekZeroTol)
        {
            chiRoe   = (D * avgChi + s * s * deltaRho * dP) / fac;
            kappaRoe = D * avgKappa / fac;
        }
        else
        {
            chiRoe   = avgChi;
            kappaRoe = avgKappa;
        }
        // Speed of sound (eq 53)
        cRoe = sqrt(chiRoe + kappaRoe * (HRoe - 0.5 * URoe2));
    }
    return cRoe;
}
 
} // namespace Nektar