Nektar::LaxFriedrichsSolver Class Reference

#include <LaxFriedrichsSolver.h>

Inheritance diagram for Nektar::LaxFriedrichsSolver:

Static Public Member Functions
static RiemannSolverSharedPtr	create (const LibUtilities::SessionReaderSharedPtr &pSession)
static RiemannSolverSharedPtr	create (const LibUtilities::SessionReaderSharedPtr &pSession)

Static Public Attributes
static std::string	solverName

Protected Member Functions
	LaxFriedrichsSolver (const LibUtilities::SessionReaderSharedPtr &pSession)
virtual void	v_PointSolve (double rhoL, double rhouL, double rhovL, double rhowL, double EL, double rhoR, double rhouR, double rhovR, double rhowR, double ER, double &rhof, double &rhouf, double &rhovf, double &rhowf, double &Ef)
	Lax-Friedrichs Riemann solver. More...
	LaxFriedrichsSolver (const LibUtilities::SessionReaderSharedPtr &pSession)
virtual void	v_PointSolve (NekDouble hL, NekDouble huL, NekDouble hvL, NekDouble hR, NekDouble huR, NekDouble hvR, NekDouble &hf, NekDouble &huf, NekDouble &hvf)
	Lax-Friedrichs Riemann solver. More...
Protected Member Functions inherited from Nektar::CompressibleSolver
	CompressibleSolver (const LibUtilities::SessionReaderSharedPtr &pSession)
virtual void	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)
virtual void	v_ArraySolve (const Array< OneD, const Array< OneD, NekDouble > > &Fwd, const Array< OneD, const Array< OneD, NekDouble > > &Bwd, Array< OneD, Array< OneD, NekDouble > > &flux)
virtual void	v_PointSolveVisc (NekDouble rhoL, NekDouble rhouL, NekDouble rhovL, NekDouble rhowL, NekDouble EL, NekDouble EpsL, NekDouble rhoR, NekDouble rhouR, NekDouble rhovR, NekDouble rhowR, NekDouble ER, NekDouble EpsR, NekDouble &rhof, NekDouble &rhouf, NekDouble &rhovf, NekDouble &rhowf, NekDouble &Ef, NekDouble &Epsf)
NekDouble	GetRoeSoundSpeed (NekDouble rhoL, NekDouble pL, NekDouble eL, NekDouble HL, NekDouble srL, NekDouble rhoR, NekDouble pR, NekDouble eR, NekDouble HR, NekDouble srR, NekDouble HRoe, NekDouble URoe2, NekDouble srLR)
Protected Member Functions inherited from Nektar::SolverUtils::RiemannSolver
SOLVER_UTILS_EXPORT	RiemannSolver (const LibUtilities::SessionReaderSharedPtr &pSession)
virtual SOLVER_UTILS_EXPORT	~RiemannSolver ()
void	GenerateRotationMatrices (const Array< OneD, const Array< OneD, NekDouble > > &normals)
	Generate rotation matrices for 3D expansions. More...
void	FromToRotation (Array< OneD, const NekDouble > &from, Array< OneD, const NekDouble > &to, NekDouble *mat)
	A function for creating a rotation matrix that rotates a vector from into another vector to. More...
SOLVER_UTILS_EXPORT void	rotateToNormal (const Array< OneD, const Array< OneD, NekDouble > > &inarray, const Array< OneD, const Array< OneD, NekDouble > > &normals, const Array< OneD, const Array< OneD, NekDouble > > &vecLocs, Array< OneD, Array< OneD, NekDouble > > &outarray)
	Rotate a vector field to trace normal. More...
SOLVER_UTILS_EXPORT void	rotateFromNormal (const Array< OneD, const Array< OneD, NekDouble > > &inarray, const Array< OneD, const Array< OneD, NekDouble > > &normals, const Array< OneD, const Array< OneD, NekDouble > > &vecLocs, Array< OneD, Array< OneD, NekDouble > > &outarray)
	Rotate a vector field from trace normal. More...
SOLVER_UTILS_EXPORT bool	CheckScalars (std::string name)
	Determine whether a scalar has been defined in m_scalars. More...
SOLVER_UTILS_EXPORT bool	CheckVectors (std::string name)
	Determine whether a vector has been defined in m_vectors. More...
SOLVER_UTILS_EXPORT bool	CheckParams (std::string name)
	Determine whether a parameter has been defined in m_params. More...
SOLVER_UTILS_EXPORT bool	CheckAuxScal (std::string name)
	Determine whether a scalar has been defined in m_auxScal. More...
SOLVER_UTILS_EXPORT bool	CheckAuxVec (std::string name)
	Determine whether a vector has been defined in m_auxVec. More...
Protected Member Functions inherited from Nektar::NonlinearSWESolver
	NonlinearSWESolver (const LibUtilities::SessionReaderSharedPtr &pSession)
virtual void	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)
virtual void	v_ArraySolve (const Array< OneD, const Array< OneD, NekDouble > > &Fwd, const Array< OneD, const Array< OneD, NekDouble > > &Bwd, Array< OneD, Array< OneD, NekDouble > > &flux)

Additional Inherited Members
Public Member Functions inherited from Nektar::SolverUtils::RiemannSolver
SOLVER_UTILS_EXPORT void	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)
	Perform the Riemann solve given the forwards and backwards spaces. More...
template<typename FuncPointerT , typename ObjectPointerT >
void	SetScalar (std::string name, FuncPointerT func, ObjectPointerT obj)
void	SetScalar (std::string name, RSScalarFuncType fp)
template<typename FuncPointerT , typename ObjectPointerT >
void	SetVector (std::string name, FuncPointerT func, ObjectPointerT obj)
void	SetVector (std::string name, RSVecFuncType fp)
template<typename FuncPointerT , typename ObjectPointerT >
void	SetParam (std::string name, FuncPointerT func, ObjectPointerT obj)
void	SetParam (std::string name, RSParamFuncType fp)
template<typename FuncPointerT , typename ObjectPointerT >
void	SetAuxScal (std::string name, FuncPointerT func, ObjectPointerT obj)
template<typename FuncPointerT , typename ObjectPointerT >
void	SetAuxVec (std::string name, FuncPointerT func, ObjectPointerT obj)
std::map< std::string, RSScalarFuncType > &	GetScalars ()
std::map< std::string, RSVecFuncType > &	GetVectors ()
std::map< std::string, RSParamFuncType > &	GetParams ()
Public Attributes inherited from Nektar::SolverUtils::RiemannSolver
int	m_spacedim
Protected Attributes inherited from Nektar::CompressibleSolver
bool	m_pointSolve
EquationOfStateSharedPtr	m_eos
bool	m_idealGas
Protected Attributes inherited from Nektar::SolverUtils::RiemannSolver
bool	m_requiresRotation
	Indicates whether the Riemann solver requires a rotation to be applied to the velocity fields. More...
std::map< std::string, RSScalarFuncType >	m_scalars
	Map of scalar function types. More...
std::map< std::string, RSVecFuncType >	m_vectors
	Map of vector function types. More...
std::map< std::string, RSParamFuncType >	m_params
	Map of parameter function types. More...
std::map< std::string, RSScalarFuncType >	m_auxScal
	Map of auxiliary scalar function types. More...
std::map< std::string, RSVecFuncType >	m_auxVec
	Map of auxiliary vector function types. More...
Array< OneD, Array< OneD, NekDouble > >	m_rotMat
	Rotation matrices for each trace quadrature point. More...
Array< OneD, Array< OneD, Array< OneD, NekDouble > > >	m_rotStorage
	Rotation storage. More...
Protected Attributes inherited from Nektar::NonlinearSWESolver
bool	m_pointSolve

Detailed Description

Definition at line 42 of file CompressibleFlowSolver/RiemannSolvers/LaxFriedrichsSolver.h.

Constructor & Destructor Documentation

LaxFriedrichsSolver() [1/2]

Nektar::LaxFriedrichsSolver::LaxFriedrichsSolver ( const LibUtilities::SessionReaderSharedPtr &  pSession )

protected

Definition at line 45 of file CompressibleFlowSolver/RiemannSolvers/LaxFriedrichsSolver.cpp.

        : CompressibleSolver(pSession)
    {
        
    }

Referenced by create().

LaxFriedrichsSolver() [2/2]

Nektar::LaxFriedrichsSolver::LaxFriedrichsSolver ( const LibUtilities::SessionReaderSharedPtr &  pSession )

protected

Member Function Documentation

create() [1/2]

static RiemannSolverSharedPtr Nektar::LaxFriedrichsSolver::create ( const LibUtilities::SessionReaderSharedPtr &  pSession )

inlinestatic

Definition at line 45 of file CompressibleFlowSolver/RiemannSolvers/LaxFriedrichsSolver.h.

        {
            return RiemannSolverSharedPtr(
                new LaxFriedrichsSolver(pSession));
        }

References LaxFriedrichsSolver().

create() [2/2]

static RiemannSolverSharedPtr Nektar::LaxFriedrichsSolver::create ( const LibUtilities::SessionReaderSharedPtr &  pSession )

inlinestatic

Definition at line 45 of file ShallowWaterSolver/RiemannSolvers/LaxFriedrichsSolver.h.

        {
            return RiemannSolverSharedPtr(
                new LaxFriedrichsSolver(pSession));
        }

References LaxFriedrichsSolver().

v_PointSolve() [1/2]

void Nektar::LaxFriedrichsSolver::v_PointSolve ( double  rhoL, double  rhouL, double  rhovL, double  rhowL, double  EL, double  rhoR, double  rhouR, double  rhovR, double  rhowR, double  ER, double &  rhof, double &  rhouf, double &  rhovf, double &  rhowf, double &  Ef  )

protectedvirtual

Lax-Friedrichs Riemann solver.

Parameters

rhoL	Density left state.
rhoR	Density right state.
rhouL	x-momentum component left state.
rhouR	x-momentum component right state.
rhovL	y-momentum component left state.
rhovR	y-momentum component right state.
rhowL	z-momentum component left state.
rhowR	z-momentum component right state.
EL	Energy left state.
ER	Energy right state.
rhof	Computed Riemann flux for density.
rhouf	Computed Riemann flux for x-momentum component
rhovf	Computed Riemann flux for y-momentum component
rhowf	Computed Riemann flux for z-momentum component
Ef	Computed Riemann flux for energy.

Reimplemented from Nektar::CompressibleSolver.

Definition at line 71 of file CompressibleFlowSolver/RiemannSolvers/LaxFriedrichsSolver.cpp.

    {
        // Left and right velocities
        NekDouble uL = rhouL / rhoL;
        NekDouble vL = rhovL / rhoL;
        NekDouble wL = rhowL / rhoL;
        NekDouble uR = rhouR / rhoR;
        NekDouble vR = rhovR / rhoR;
        NekDouble wR = rhowR / rhoR;
 
        // Internal energy (per unit mass)
        NekDouble eL =
                (EL - 0.5 * (rhouL * uL + rhovL * vL + rhowL * wL)) / rhoL;
        NekDouble eR =
                (ER - 0.5 * (rhouR * uR + rhovR * vR + rhowR * wR)) / rhoR;
        // Pressure
        NekDouble pL = m_eos->GetPressure(rhoL, eL);
        NekDouble pR = m_eos->GetPressure(rhoR, eR);
 
        // Left and right total enthalpy
        NekDouble HL = (EL + pL) / rhoL;
        NekDouble HR = (ER + pR) / rhoR;
 
        // Square root of rhoL and rhoR.
        NekDouble srL  = sqrt(rhoL);
        NekDouble srR  = sqrt(rhoR);
        NekDouble srLR = srL + srR;
        
        // Roe average state
        NekDouble uRoe   = (srL * uL + srR * uR) / srLR;
        NekDouble vRoe   = (srL * vL + srR * vR) / srLR;
        NekDouble wRoe   = (srL * wL + srR * wR) / srLR;
        NekDouble URoe2  = uRoe*uRoe + vRoe*vRoe + wRoe*wRoe;
        NekDouble HRoe   = (srL * HL + srR * HR) / srLR;
        NekDouble cRoe   = GetRoeSoundSpeed(
                                rhoL, pL, eL, HL, srL,
                                rhoR, pR, eR, HR, srR,
                                HRoe, URoe2, srLR);
 
        // Maximum eigenvalue
        NekDouble URoe = fabs(uRoe) + cRoe;
        
        // Lax-Friedrichs flux formula
        rhof  = 0.5*(rhouL + rhouR - URoe*(rhoR - rhoL));
        rhouf = 0.5*(pL + rhouL*uL + pR + rhouR*uR - URoe*(rhouR - rhouL));
        rhovf = 0.5*(rhouL*vL + rhouR*vR - URoe*(rhovR - rhovL));
        rhowf = 0.5*(rhouL*wL + rhouR*wR - URoe*(rhowR - rhowL));
        Ef    = 0.5*(uL*(EL + pL) + uR*(ER + pR) - URoe*(ER - EL));
    }

References Nektar::CompressibleSolver::GetRoeSoundSpeed(), and Nektar::CompressibleSolver::m_eos.

v_PointSolve() [2/2]

void Nektar::LaxFriedrichsSolver::v_PointSolve ( NekDouble  hL, NekDouble  huL, NekDouble  hvL, NekDouble  hR, NekDouble  huR, NekDouble  hvR, NekDouble &  hf, NekDouble &  huf, NekDouble &  hvf  )

protectedvirtual

Lax-Friedrichs Riemann solver.

Parameters

hL	Water depth left state.
hR	Water depth right state.
huL	x-momentum component left state.
huR	x-momentum component right state.
hvL	y-momentum component left state.
hvR	y-momentum component right state.
hf	Computed Riemann flux for density.
huf	Computed Riemann flux for x-momentum component
hvf	Computed Riemann flux for y-momentum component

Reimplemented from Nektar::NonlinearSWESolver.

Definition at line 65 of file ShallowWaterSolver/RiemannSolvers/LaxFriedrichsSolver.cpp.

    {        
        static NekDouble g = m_params["gravity"]();
        
        // Left and right velocities
        NekDouble uL = huL / hL;
        NekDouble vL = hvL / hL;
        NekDouble uR = huR / hR;
        NekDouble vR = hvR / hR;
                
        // Left and right wave speeds
        NekDouble cL = sqrt(g * hL);
        NekDouble cR = sqrt(g * hR);
        
          // Square root of hL and hR.
        NekDouble srL  = sqrt(hL);
        NekDouble srR  = sqrt(hR);
        NekDouble srLR = srL + srR;
        
        // Velocity Roe averages
        NekDouble uRoe   = (srL * uL + srR * uR) / srLR;
        NekDouble cRoe   = sqrt(0.5 * (cL * cL + cR * cR));
        
        // Minimum and maximum wave speeds
        NekDouble S    = std::max(uRoe+cRoe, std::max(uR+cR, -(uL-cL)));
        NekDouble sign = 1.0;
        
        if(S == -(uL-cL))
        {
            sign = -1.0;
        }
        
        // Lax-Friedrichs Riemann h flux
        hf  = 0.5 * ((huL + huR) - sign * S * (hR -hL));
        
        // Lax-Friedrichs Riemann hu flux
        huf = 0.5 * ((hL * uL * uL + 0.5 * g * hL * hL  + 
                      hR * uR * uR + 0.5 * g * hR * hR) - 
                       sign * S * (huR - huL));
        
        // Lax-Friedrichs Riemann hv flux
        hvf = 0.5 * ((hL * uL * vL + hR * uR * vR) - 
                        sign * S * (hvR - hvL));
        
    }

References sign.

Member Data Documentation

solverName

static std::string Nektar::LaxFriedrichsSolver::solverName

static

Initial value:

=
        SolverUtils::GetRiemannSolverFactory().RegisterCreatorFunction(
            "LaxFriedrichs",
            LaxFriedrichsSolver::create,
            "Lax-Friedrichs Riemann solver")

Definition at line 52 of file CompressibleFlowSolver/RiemannSolvers/LaxFriedrichsSolver.h.