Nektar::ArtificialDiffusion Class Reference

Encapsulates the artificial diffusion used in shock capture. More...

#include <ArtificialDiffusion.h>

Inheritance diagram for Nektar::ArtificialDiffusion:

Public Member Functions
void	DoArtificialDiffusion (const Array< OneD, const Array< OneD, NekDouble > > &inarray, Array< OneD, Array< OneD, NekDouble > > &outarray)
	Apply the artificial diffusion. More...
void	DoArtificialDiffusionCoeff (const Array< OneD, const Array< OneD, NekDouble > > &inarray, Array< OneD, Array< OneD, NekDouble > > &outarray)
	Apply the artificial diffusion the outarray is in coeff space. More...
void	GetArtificialViscosity (const Array< OneD, Array< OneD, NekDouble > > &physfield, Array< OneD, NekDouble > &mu)
	Calculate the artificial viscosity. More...

Protected Member Functions
	ArtificialDiffusion (const LibUtilities::SessionReaderSharedPtr &pSession, const Array< OneD, MultiRegions::ExpListSharedPtr > &pFields, const int spacedim)
	Constructor. More...
virtual	~ArtificialDiffusion ()=default
virtual void	v_DoArtificialDiffusion (const Array< OneD, const Array< OneD, NekDouble > > &inarray, Array< OneD, Array< OneD, NekDouble > > &outarray)
virtual void	v_DoArtificialDiffusionCoeff (const Array< OneD, const Array< OneD, NekDouble > > &inarray, Array< OneD, Array< OneD, NekDouble > > &outarray)
virtual void	v_GetArtificialViscosity (const Array< OneD, Array< OneD, NekDouble > > &physfield, Array< OneD, NekDouble > &mu)=0
void	GetFluxVector (const Array< OneD, Array< OneD, NekDouble > > &inarray, const Array< OneD, Array< OneD, Array< OneD, NekDouble > > > &qfield, Array< OneD, Array< OneD, Array< OneD, NekDouble > > > &viscousTensor)
	Return the flux vector for the artificial viscosity operator. More...

Protected Attributes
LibUtilities::SessionReaderSharedPtr	m_session
	Session reader. More...
Array< OneD, MultiRegions::ExpListSharedPtr >	m_fields
	Array of fields. More...
VariableConverterSharedPtr	m_varConv
	Auxiliary object to convert variables. More...
SolverUtils::DiffusionSharedPtr	m_diffusion
	LDG Diffusion operator. More...
NekDouble	m_mu0
	Constant scaling. More...

Detailed Description

Encapsulates the artificial diffusion used in shock capture.

Definition at line 69 of file ArtificialDiffusion.h.

Constructor & Destructor Documentation

ArtificialDiffusion()

Nektar::ArtificialDiffusion::ArtificialDiffusion ( const LibUtilities::SessionReaderSharedPtr &  pSession, const Array< OneD, MultiRegions::ExpListSharedPtr > &  pFields, const int  spacedim  )

protected

Constructor.

Definition at line 47 of file ArtificialDiffusion.cpp.

    : m_session(pSession), m_fields(pFields)
{
    // Create auxiliary object to convert variables
    m_varConv = MemoryManager<VariableConverter>::AllocateSharedPtr(m_session,
                                                                    spacedim);
 
    m_diffusion =
        SolverUtils::GetDiffusionFactory().CreateInstance("LDG", "LDG");
    m_diffusion->SetFluxVector(&ArtificialDiffusion::GetFluxVector, this);
    m_diffusion->InitObject(m_session, m_fields);
 
    // Get constant scaling
    m_session->LoadParameter("mu0", m_mu0, 1.0);
}

References Nektar::MemoryManager< DataType >::AllocateSharedPtr(), Nektar::LibUtilities::NekFactory< tKey, tBase, tParam >::CreateInstance(), Nektar::SolverUtils::GetDiffusionFactory(), GetFluxVector(), m_diffusion, m_fields, m_mu0, m_session, and m_varConv.

~ArtificialDiffusion()

virtual Nektar::ArtificialDiffusion::~ArtificialDiffusion ( )

protectedvirtualdefault

Member Function Documentation

DoArtificialDiffusion()

void Nektar::ArtificialDiffusion::DoArtificialDiffusion ( const Array< OneD, const Array< OneD, NekDouble > > &  inarray, Array< OneD, Array< OneD, NekDouble > > &  outarray  )

inline

Apply the artificial diffusion.

Definition at line 73 of file ArtificialDiffusion.h.

    {
        v_DoArtificialDiffusion(inarray, outarray);
    }

References v_DoArtificialDiffusion().

DoArtificialDiffusionCoeff()

void Nektar::ArtificialDiffusion::DoArtificialDiffusionCoeff ( const Array< OneD, const Array< OneD, NekDouble > > &  inarray, Array< OneD, Array< OneD, NekDouble > > &  outarray  )

inline

Apply the artificial diffusion the outarray is in coeff space.

Definition at line 81 of file ArtificialDiffusion.h.

    {
        v_DoArtificialDiffusionCoeff(inarray, outarray);
    }

References v_DoArtificialDiffusionCoeff().

GetArtificialViscosity()

void Nektar::ArtificialDiffusion::GetArtificialViscosity ( const Array< OneD, Array< OneD, NekDouble > > &  physfield, Array< OneD, NekDouble > &  mu  )

inline

Calculate the artificial viscosity.

Definition at line 89 of file ArtificialDiffusion.h.

    {
        v_GetArtificialViscosity(physfield, mu);
    }

References v_GetArtificialViscosity().

Referenced by GetFluxVector().

GetFluxVector()

void Nektar::ArtificialDiffusion::GetFluxVector ( const Array< OneD, Array< OneD, NekDouble > > &  inarray, const Array< OneD, Array< OneD, Array< OneD, NekDouble > > > &  qfield, Array< OneD, Array< OneD, Array< OneD, NekDouble > > > &  viscousTensor  )

protected

Return the flux vector for the artificial viscosity operator.

Definition at line 121 of file ArtificialDiffusion.cpp.

{
    unsigned int nDim              = qfield.size();
    unsigned int nConvectiveFields = qfield[0].size();
    unsigned int nPts              = qfield[0][0].size();
 
    // Get Artificial viscosity
    Array<OneD, NekDouble> mu{nPts, 0.0};
    GetArtificialViscosity(inarray, mu);
 
    // Compute viscous tensor
    for (unsigned int j = 0; j < nDim; ++j)
    {
        for (unsigned int i = 0; i < nConvectiveFields; ++i)
        {
            Vmath::Vmul(nPts, qfield[j][i], 1, mu, 1, viscousTensor[j][i], 1);
        }
    }
}

References GetArtificialViscosity(), and Vmath::Vmul().

Referenced by ArtificialDiffusion().

v_DoArtificialDiffusion()

void Nektar::ArtificialDiffusion::v_DoArtificialDiffusion ( const Array< OneD, const Array< OneD, NekDouble > > &  inarray, Array< OneD, Array< OneD, NekDouble > > &  outarray  )

protectedvirtual

Definition at line 69 of file ArtificialDiffusion.cpp.

{
    int nvariables = inarray.size();
    int npoints    = m_fields[0]->GetNpoints();
 
    Array<OneD, Array<OneD, NekDouble>> outarrayDiff(nvariables);
 
    for (int i = 0; i < nvariables; ++i)
    {
        outarrayDiff[i] = Array<OneD, NekDouble>(npoints, 0.0);
    }
 
    m_diffusion->Diffuse(nvariables, m_fields, inarray, outarrayDiff);
 
    for (int i = 0; i < nvariables; ++i)
    {
        Vmath::Vadd(npoints, outarray[i], 1, outarrayDiff[i], 1, outarray[i],
                    1);
    }
}

References m_diffusion, m_fields, and Vmath::Vadd().

Referenced by DoArtificialDiffusion().

v_DoArtificialDiffusionCoeff()

void Nektar::ArtificialDiffusion::v_DoArtificialDiffusionCoeff ( const Array< OneD, const Array< OneD, NekDouble > > &  inarray, Array< OneD, Array< OneD, NekDouble > > &  outarray  )

protectedvirtual

Definition at line 95 of file ArtificialDiffusion.cpp.

{
    size_t nvariables = inarray.size();
    size_t ncoeffs    = m_fields[0]->GetNcoeffs();
 
    Array<OneD, Array<OneD, NekDouble>> outarrayDiff{nvariables};
 
    for (size_t i = 0; i < nvariables; ++i)
    {
        outarrayDiff[i] = Array<OneD, NekDouble>{ncoeffs, 0.0};
    }
 
    m_diffusion->DiffuseCoeffs(nvariables, m_fields, inarray, outarrayDiff);
 
    for (size_t i = 0; i < nvariables; ++i)
    {
        Vmath::Vadd(ncoeffs, outarray[i], 1, outarrayDiff[i], 1, outarray[i],
                    1);
    }
}

References m_diffusion, m_fields, and Vmath::Vadd().

Referenced by DoArtificialDiffusionCoeff().

v_GetArtificialViscosity()

virtual void Nektar::ArtificialDiffusion::v_GetArtificialViscosity ( const Array< OneD, Array< OneD, NekDouble > > &  physfield, Array< OneD, NekDouble > &  mu  )

protectedpure virtual

Implemented in Nektar::NonSmoothShockCapture.

Referenced by GetArtificialViscosity().

Member Data Documentation

m_diffusion

SolverUtils::DiffusionSharedPtr Nektar::ArtificialDiffusion::m_diffusion

protected

LDG Diffusion operator.

Definition at line 104 of file ArtificialDiffusion.h.

Referenced by ArtificialDiffusion(), v_DoArtificialDiffusion(), and v_DoArtificialDiffusionCoeff().

m_fields

Array<OneD, MultiRegions::ExpListSharedPtr> Nektar::ArtificialDiffusion::m_fields

protected

Array of fields.

Definition at line 100 of file ArtificialDiffusion.h.

Referenced by ArtificialDiffusion(), Nektar::NonSmoothShockCapture::NonSmoothShockCapture(), v_DoArtificialDiffusion(), v_DoArtificialDiffusionCoeff(), and Nektar::NonSmoothShockCapture::v_GetArtificialViscosity().

m_mu0

NekDouble Nektar::ArtificialDiffusion::m_mu0

protected

Constant scaling.

Definition at line 106 of file ArtificialDiffusion.h.

Referenced by ArtificialDiffusion(), and Nektar::NonSmoothShockCapture::v_GetArtificialViscosity().

m_session

LibUtilities::SessionReaderSharedPtr Nektar::ArtificialDiffusion::m_session

protected

Session reader.

Definition at line 98 of file ArtificialDiffusion.h.

Referenced by ArtificialDiffusion(), and Nektar::NonSmoothShockCapture::NonSmoothShockCapture().

m_varConv

VariableConverterSharedPtr Nektar::ArtificialDiffusion::m_varConv

protected

Auxiliary object to convert variables.

Definition at line 102 of file ArtificialDiffusion.h.

Referenced by ArtificialDiffusion(), Nektar::NonSmoothShockCapture::NonSmoothShockCapture(), and Nektar::NonSmoothShockCapture::v_GetArtificialViscosity().