Nektar::RCROutflow Class Reference

#include <RCROutflow.h>

Inheritance diagram for Nektar::RCROutflow:

Public Member Functions
	RCROutflow (Array< OneD, MultiRegions::ExpListSharedPtr > pVessel, const LibUtilities::SessionReaderSharedPtr pSession, PulseWavePressureAreaSharedPtr pressureArea)
	~RCROutflow () override
Public Member Functions inherited from Nektar::PulseWaveBoundary
	PulseWaveBoundary (Array< OneD, MultiRegions::ExpListSharedPtr > &pVessel, const LibUtilities::SessionReaderSharedPtr &pSession, PulseWavePressureAreaSharedPtr &pressureArea)
virtual	~PulseWaveBoundary ()
void	DoBoundary (const Array< OneD, const Array< OneD, NekDouble > > &inarray, Array< OneD, Array< OneD, NekDouble > > &A_0, Array< OneD, Array< OneD, NekDouble > > &beta, Array< OneD, Array< OneD, NekDouble > > &alpha, const NekDouble time, int omega, int offset, int n)

Static Public Member Functions
static PulseWaveBoundarySharedPtr	create (Array< OneD, MultiRegions::ExpListSharedPtr > &pVessel, const LibUtilities::SessionReaderSharedPtr &pSession, PulseWavePressureAreaSharedPtr &pressureArea)

Static Public Attributes
static std::string	className

Protected Member Functions
void	v_DoBoundary (const Array< OneD, const Array< OneD, NekDouble > > &inarray, Array< OneD, Array< OneD, NekDouble > > &A_0, Array< OneD, Array< OneD, NekDouble > > &beta, Array< OneD, Array< OneD, NekDouble > > &alpha, const NekDouble time, int omega, int offset, int n) override
void	R_RiemannSolver (NekDouble R, NekDouble A_l, NekDouble u_l, NekDouble A_0, NekDouble beta, NekDouble alpha, NekDouble POut, NekDouble &A_u, NekDouble &u_u)
virtual void	v_DoBoundary (const Array< OneD, const Array< OneD, NekDouble > > &inarray, Array< OneD, Array< OneD, NekDouble > > &A_0, Array< OneD, Array< OneD, NekDouble > > &beta, Array< OneD, Array< OneD, NekDouble > > &alpha, const NekDouble time, int omega, int offset, int n)=0

Protected Attributes
NekDouble	m_timestep
NekDouble	m_pc = 0.0
Protected Attributes inherited from Nektar::PulseWaveBoundary
Array< OneD, MultiRegions::ExpListSharedPtr >	m_vessels
LibUtilities::SessionReaderSharedPtr	m_session
PulseWavePressureAreaSharedPtr	m_pressureArea
NekDouble	m_pext
NekDouble	m_pout
NekDouble	m_rho

Detailed Description

Definition at line 52 of file RCROutflow.h.

Constructor & Destructor Documentation

RCROutflow()

Nektar::RCROutflow::RCROutflow	(	Array< OneD, MultiRegions::ExpListSharedPtr >	pVessel,
		const LibUtilities::SessionReaderSharedPtr	pSession,
		PulseWavePressureAreaSharedPtr	pressureArea
	)

Definition at line 48 of file RCROutflow.cpp.

    : PulseWaveBoundary(pVessel, pSession, pressureArea)
{
    m_session->LoadParameter("TimeStep", m_timestep);
}

References Nektar::PulseWaveBoundary::m_session, and m_timestep.

~RCROutflow()

Nektar::RCROutflow::~RCROutflow ( )

override

Definition at line 56 of file RCROutflow.cpp.

{
}

Member Function Documentation

create()

static PulseWaveBoundarySharedPtr Nektar::RCROutflow::create ( Array< OneD, MultiRegions::ExpListSharedPtr > &  pVessel, const LibUtilities::SessionReaderSharedPtr &  pSession, PulseWavePressureAreaSharedPtr &  pressureArea  )

inlinestatic

Definition at line 56 of file RCROutflow.h.

    {
        return MemoryManager<RCROutflow>::AllocateSharedPtr(pVessel, pSession,
                                                            pressureArea);
    }

References Nektar::MemoryManager< DataType >::AllocateSharedPtr().

R_RiemannSolver()

void Nektar::RCROutflow::R_RiemannSolver ( NekDouble  R, NekDouble  A_l, NekDouble  u_l, NekDouble  A_0, NekDouble  beta, NekDouble  alpha, NekDouble  POut, NekDouble &  A_u, NekDouble &  u_u  )

protected

Definition at line 133 of file RCROutflow.cpp.

{
    NekDouble W1           = 0.0;
    NekDouble c            = 0.0;
    NekDouble cL           = 0.0;
    NekDouble I            = 0.0;
    NekDouble A_calc       = 0.0;
    NekDouble FA           = 0.0;
    NekDouble dFdA         = 0.0;
    NekDouble delta_A_calc = 0.0;
    NekDouble P            = 0.0;
    NekDouble rho          = m_rho;
 
    int proceed  = 1;
    int iter     = 0;
    int MAX_ITER = 100;
 
    // Tolerances for the algorithm
    NekDouble Tol = 1.0E-10;
 
    // Calculate the wave speed
    m_pressureArea->GetC(cL, beta, A_l, A_0, alpha);
 
    // Riemann invariant \f$W_1(Al,ul)\f$
    m_pressureArea->GetW1(W1, u_l, beta, A_l, A_0, alpha);
 
    // Newton Iteration (Area only)
    A_calc = A_l;
    while ((proceed) && (iter < MAX_ITER))
    {
        iter += 1;
 
        m_pressureArea->GetPressure(P, beta, A_calc, A_0, 0, 0, alpha);
        m_pressureArea->GetC(c, beta, A_calc, A_0, alpha);
        m_pressureArea->GetCharIntegral(I, beta, A_calc, A_0, alpha);
 
        FA           = R * A_calc * (W1 - I) - P + POut;
        dFdA         = R * (W1 - I - c) - c * c * rho / A_calc;
        delta_A_calc = FA / dFdA;
        A_calc -= delta_A_calc;
 
        if (sqrt(delta_A_calc * delta_A_calc) < Tol)
        {
            proceed = 0;
        }
    }
 
    m_pressureArea->GetPressure(P, beta, A_calc, A_0, 0, 0, alpha);
 
    // Obtain u_u and A_u
    u_u = (P - POut) / (R * A_calc);
    A_u = A_calc;
}

References Nektar::LibUtilities::beta, Nektar::PulseWaveBoundary::m_pressureArea, Nektar::PulseWaveBoundary::m_rho, Nektar::LibUtilities::P, and tinysimd::sqrt().

Referenced by v_DoBoundary().

v_DoBoundary()

void Nektar::RCROutflow::v_DoBoundary ( const Array< OneD, const Array< OneD, NekDouble > > &  inarray, Array< OneD, Array< OneD, NekDouble > > &  A_0, Array< OneD, Array< OneD, NekDouble > > &  beta, Array< OneD, Array< OneD, NekDouble > > &  alpha, const NekDouble  time, int  omega, int  offset, int  n  )

overrideprotectedvirtual

Implements Nektar::PulseWaveBoundary.

Definition at line 60 of file RCROutflow.cpp.

{
    NekDouble A_r  = 0.0;
    NekDouble u_r  = 0.0;
    NekDouble A_u  = 0.0;
    NekDouble u_u  = 0.0;
    NekDouble A_l  = 0.0;
    NekDouble u_l  = 0.0;
    NekDouble c_0  = 0.0;
    NekDouble R1   = 0.0;
    NekDouble R2   = 0.0;
    NekDouble POut = m_pout;
    NekDouble rho  = m_rho;
 
    Array<OneD, MultiRegions::ExpListSharedPtr> vessel(2);
 
    // Pointers to the domains
    vessel[0] = m_vessels[2 * omega];
    vessel[1] = m_vessels[2 * omega + 1];
 
    /* Find the terminal RCR boundary condition and calculates
       the updated velocity and area as well as the updated
       boundary conditions */
 
    /* Load terminal resistance, capacitance, outflow pressure,
       and number of points from the input file */
    NekDouble RT = ((vessel[0]->GetBndCondExpansions())[n])->GetCoeffs()[0];
    NekDouble C  = ((vessel[1]->GetBndCondExpansions())[n])->GetCoeffs()[0];
    int nq       = vessel[0]->GetTotPoints();
 
    // Get the values of all variables needed for the Riemann problem
    A_l = inarray[0][offset + nq - 1];
    u_l = inarray[1][offset + nq - 1];
 
    // Goes through the first resistance; calculates c_0
    m_pressureArea->GetC(c_0, beta[omega][nq - 1], A_0[omega][nq - 1],
                         A_0[omega][nq - 1], alpha[omega][nq - 1]);
 
    /* Calculate R1 and R2, R1 being calculated so as
       to eliminate reflections in the vessel */
    R1 = rho * c_0 / A_0[omega][nq - 1];
 
    if (R1 > 0.9 * RT)
    {
        // In case the resistance is lower than the characteristic impedance.
        R1 = 0.9 * RT;
    }
 
    R2 = RT - R1;
 
    // Call the R RiemannSolver
    R_RiemannSolver(R1, A_l, u_l, A_0[omega][nq - 1], beta[omega][nq - 1],
                    alpha[omega][nq - 1], m_pc, A_u, u_u);
 
    /* Fix the boundary conditions in the virtual region to ensure
       upwind state matches the boundary condition at the next time step */
    A_r = A_l;
    u_r = 2 * u_u - u_l;
 
    /* Goes through the CR system, which
       just updates the pressure pc */
    m_pc += (m_timestep / C) * (A_u * u_u - (m_pc - POut) / R2);
 
    // Store the updated values
    (vessel[0]->UpdateBndCondExpansion(n))->UpdatePhys()[0] = A_r;
    (vessel[1]->UpdateBndCondExpansion(n))->UpdatePhys()[0] = u_r;
}

References Nektar::LibUtilities::beta, m_pc, Nektar::PulseWaveBoundary::m_pout, Nektar::PulseWaveBoundary::m_pressureArea, Nektar::PulseWaveBoundary::m_rho, m_timestep, Nektar::PulseWaveBoundary::m_vessels, and R_RiemannSolver().

Member Data Documentation

className

std::string Nektar::RCROutflow::className

static

Initial value:

=
    GetBoundaryFactory().RegisterCreatorFunction(
        "RCR-terminal", RCROutflow::create, "RCR outflow boundary condition")

Definition at line 66 of file RCROutflow.h.

m_pc

NekDouble Nektar::RCROutflow::m_pc = 0.0

protected

Definition at line 87 of file RCROutflow.h.

Referenced by v_DoBoundary().

m_timestep

NekDouble Nektar::RCROutflow::m_timestep

protected

Definition at line 86 of file RCROutflow.h.

Referenced by RCROutflow(), and v_DoBoundary().