GRINS::IncompressibleNavierStokes< Viscosity > Class Template Reference

Physics class for Incompressible Navier-Stokes. More...

#include <inc_navier_stokes.h>

Inheritance diagram for GRINS::IncompressibleNavierStokes< Viscosity >:

Collaboration diagram for GRINS::IncompressibleNavierStokes< Viscosity >:

Public Member Functions
	IncompressibleNavierStokes (const std::string &physics_name, const GetPot &input)
	~IncompressibleNavierStokes ()
virtual void	auxiliary_init (MultiphysicsSystem &system)
	Any auxillary initialization a Physics class may need. More...
virtual void	register_postprocessing_vars (const GetPot &input, PostProcessedQuantities< libMesh::Real > &postprocessing)
	Register postprocessing variables for IncompressibleNavierStokes. More...
virtual void	element_time_derivative (bool compute_jacobian, AssemblyContext &context, CachedValues &cache)
	Time dependent part(s) of physics for element interiors. More...
virtual void	element_constraint (bool compute_jacobian, AssemblyContext &context, CachedValues &cache)
	Constraint part(s) of physics for element interiors. More...
virtual void	mass_residual (bool compute_jacobian, AssemblyContext &context, CachedValues &cache)
	Mass matrix part(s) for element interiors. All boundary terms lie within the time_derivative part. More...
virtual void	compute_postprocessed_quantity (unsigned int quantity_index, const AssemblyContext &context, const libMesh::Point &point, libMesh::Real &value)
	Compute value of postprocessed quantities at libMesh::Point. More...
Public Member Functions inherited from GRINS::IncompressibleNavierStokesBase< Viscosity >
	IncompressibleNavierStokesBase (const std::string &my_physics_name, const std::string &core_physics_name, const GetPot &input)
	~IncompressibleNavierStokesBase ()
virtual void	init_variables (libMesh::FEMSystem *system)
	Initialization of Navier-Stokes variables. More...
virtual void	set_time_evolving_vars (libMesh::FEMSystem *system)
	Sets velocity variables to be time-evolving. More...
virtual void	init_context (AssemblyContext &context)
	Initialize context for added physics variables. More...
virtual void	register_parameter (const std::string &param_name, libMesh::ParameterMultiAccessor< libMesh::Number > &param_pointer) const
	Each subclass will register its copy of an independent. More...
libMesh::Real	get_viscosity_value (AssemblyContext &context, unsigned int qp) const
Public Member Functions inherited from GRINS::Physics
	Physics (const GRINS::PhysicsName &physics_name, const GetPot &input)
virtual	~Physics ()
virtual bool	enabled_on_elem (const libMesh::Elem *elem)
	Find if current physics is active on supplied element. More...
void	set_is_steady (bool is_steady)
	Sets whether this physics is to be solved with a steady solver or not. More...
bool	is_steady () const
	Returns whether or not this physics is being solved with a steady solver. More...
virtual void	side_time_derivative (bool compute_jacobian, AssemblyContext &context, CachedValues &cache)
	Time dependent part(s) of physics for boundaries of elements on the domain boundary. More...
virtual void	nonlocal_time_derivative (bool compute_jacobian, AssemblyContext &context, CachedValues &cache)
	Time dependent part(s) of physics for scalar variables. More...
virtual void	side_constraint (bool compute_jacobian, AssemblyContext &context, CachedValues &cache)
	Constraint part(s) of physics for boundaries of elements on the domain boundary. More...
virtual void	nonlocal_constraint (bool compute_jacobian, AssemblyContext &context, CachedValues &cache)
	Constraint part(s) of physics for scalar variables. More...
virtual void	damping_residual (bool compute_jacobian, AssemblyContext &context, CachedValues &cache)
	Damping matrix part(s) for element interiors. All boundary terms lie within the time_derivative part. More...
virtual void	nonlocal_mass_residual (bool compute_jacobian, AssemblyContext &context, CachedValues &cache)
	Mass matrix part(s) for scalar variables. More...
void	init_ics (libMesh::FEMSystem *system, libMesh::CompositeFunction< libMesh::Number > &all_ics)
virtual void	compute_element_time_derivative_cache (const AssemblyContext &context, CachedValues &cache)
virtual void	compute_side_time_derivative_cache (const AssemblyContext &context, CachedValues &cache)
virtual void	compute_nonlocal_time_derivative_cache (const AssemblyContext &context, CachedValues &cache)
virtual void	compute_element_constraint_cache (const AssemblyContext &context, CachedValues &cache)
virtual void	compute_side_constraint_cache (const AssemblyContext &context, CachedValues &cache)
virtual void	compute_nonlocal_constraint_cache (const AssemblyContext &context, CachedValues &cache)
virtual void	compute_damping_residual_cache (const AssemblyContext &context, CachedValues &cache)
virtual void	compute_mass_residual_cache (const AssemblyContext &context, CachedValues &cache)
virtual void	compute_nonlocal_mass_residual_cache (const AssemblyContext &context, CachedValues &cache)
ICHandlingBase *	get_ic_handler ()
Public Member Functions inherited from GRINS::ParameterUser
	ParameterUser (const std::string &user_name)
virtual	~ParameterUser ()
virtual void	set_parameter (libMesh::Number &param_variable, const GetPot &input, const std::string &param_name, libMesh::Number param_default)
	Each subclass can simultaneously read a parameter value from. More...
virtual void	set_parameter (libMesh::ParsedFunction< libMesh::Number, libMesh::Gradient > &func, const GetPot &input, const std::string &func_param_name, const std::string &param_default)
	Each subclass can simultaneously read a parsed function from. More...
virtual void	set_parameter (libMesh::ParsedFEMFunction< libMesh::Number > &func, const GetPot &input, const std::string &func_param_name, const std::string &param_default)
	Each subclass can simultaneously read a parsed function from. More...
virtual void	move_parameter (const libMesh::Number &old_parameter, libMesh::Number &new_parameter)
	When cloning an object, we need to update parameter pointers. More...
virtual void	move_parameter (const libMesh::ParsedFunction< libMesh::Number, libMesh::Gradient > &old_func, libMesh::ParsedFunction< libMesh::Number, libMesh::Gradient > &new_func)
	When cloning an object, we need to update parameter pointers. More...
virtual void	move_parameter (const libMesh::ParsedFEMFunction< libMesh::Number > &old_func, libMesh::ParsedFEMFunction< libMesh::Number > &new_func)
	When cloning an object, we need to update parameter pointers. More...

Protected Attributes
PressurePinning	_p_pinning
bool	_pin_pressure
	Enable pressure pinning. More...
unsigned int	_mu_index
	Index from registering this quantity. More...
Protected Attributes inherited from GRINS::IncompressibleNavierStokesBase< Viscosity >
unsigned int	_dim
	Physical dimension of problem. More...
VelocityFEVariables	_flow_vars
PressureFEVariable	_press_var
libMesh::Number	_rho
	Material parameters, read from input. More...
Viscosity	_mu
	Viscosity object. More...
Protected Attributes inherited from GRINS::Physics
const PhysicsName	_physics_name
	Name of the physics object. Used for reading physics specific inputs. More...
GRINS::ICHandlingBase *	_ic_handler
std::set< libMesh::subdomain_id_type >	_enabled_subdomains
	Subdomains on which the current Physics class is enabled. More...

Private Member Functions
	IncompressibleNavierStokes ()

Additional Inherited Members
Static Public Member Functions inherited from GRINS::Physics
static void	set_is_axisymmetric (bool is_axisymmetric)
	Set whether we should treat the problem as axisymmetric. More...
static bool	is_axisymmetric ()
Static Public Attributes inherited from GRINS::ParameterUser
static std::string	zero_vector_function = std::string("{0}")
	A parseable function string with LIBMESH_DIM components, all 0. More...
Protected Member Functions inherited from GRINS::Physics
libMesh::UniquePtr< libMesh::FEGenericBase< libMesh::Real > >	build_new_fe (const libMesh::Elem *elem, const libMesh::FEGenericBase< libMesh::Real > *fe, const libMesh::Point p)
void	parse_enabled_subdomains (const GetPot &input, const std::string &physics_name)
Static Protected Attributes inherited from GRINS::Physics
static bool	_is_steady = false
	Caches whether or not the solver that's being used is steady or not. More...
static bool	_is_axisymmetric = false
	Caches whether we are solving an axisymmetric problem or not. More...

Detailed Description

template<class Viscosity>
class GRINS::IncompressibleNavierStokes< Viscosity >

Physics class for Incompressible Navier-Stokes.

This physics class implements the classical Incompressible Navier-Stokes equations. This is a templated class, the class Viscosity can be instantiated as a specific type (right now:ConstantViscosity or SpatiallyVaryingViscosity) to allow the user to specify a constant or spatially varying viscosity in the input file

Definition at line 44 of file inc_navier_stokes.h.

Constructor & Destructor Documentation

template<class Mu >

GRINS::IncompressibleNavierStokes< Mu >::IncompressibleNavierStokes	(	const std::string &	physics_name,
		const GetPot &	input
	)

Definition at line 42 of file inc_navier_stokes.C.

References GRINS::Physics::_ic_handler, GRINS::IncompressibleNavierStokes< Viscosity >::_pin_pressure, and GRINS::PhysicsNaming::incompressible_navier_stokes().

    : IncompressibleNavierStokesBase<Mu>(physics_name,
                                         PhysicsNaming::incompressible_navier_stokes(), /* "core" Physics name */
                                         input),
    _p_pinning(input,physics_name),
    _mu_index(0)
  {
    // This is deleted in the base class
    this->_ic_handler = new GenericICHandler( physics_name, input );

    this->_pin_pressure = input("Physics/"+PhysicsNaming::incompressible_navier_stokes()+"/pin_pressure", false );
  }

template<class Viscosity >

GRINS::IncompressibleNavierStokes< Viscosity >::~IncompressibleNavierStokes ( )

inline

Definition at line 50 of file inc_navier_stokes.h.

{};

template<class Viscosity >

GRINS::IncompressibleNavierStokes< Viscosity >::IncompressibleNavierStokes ( )

private

Member Function Documentation

template<class Mu >

void GRINS::IncompressibleNavierStokes< Mu >::auxiliary_init ( MultiphysicsSystem &  system )

virtual

Any auxillary initialization a Physics class may need.

This is called after all variables are added, so this method can safely query the MultiphysicsSystem about variable information.

Reimplemented from GRINS::Physics.

Definition at line 56 of file inc_navier_stokes.C.

  {
    if( _pin_pressure )
      _p_pinning.check_pin_location(system.get_mesh());
  }

template<class Mu >

void GRINS::IncompressibleNavierStokes< Mu >::compute_postprocessed_quantity ( unsigned int  quantity_index, const AssemblyContext &  context, const libMesh::Point &  point, libMesh::Real &  value  )

virtual

Compute value of postprocessed quantities at libMesh::Point.

Reimplemented from GRINS::Physics.

Definition at line 543 of file inc_navier_stokes.C.

  {
    if( quantity_index == this->_mu_index )
      {
        value = this->_mu(point, context.get_time());
      }

    return;
  }

template<class Mu >

void GRINS::IncompressibleNavierStokes< Mu >::element_constraint ( bool  compute_jacobian, AssemblyContext &  context, CachedValues &  cache  )

virtual

Constraint part(s) of physics for element interiors.

Reimplemented from GRINS::Physics.

Definition at line 331 of file inc_navier_stokes.C.

References GRINS::Physics::is_axisymmetric().

  {
#ifdef GRINS_USE_GRVY_TIMERS
    this->_timer->BeginTimer("IncompressibleNavierStokes::element_constraint");
#endif

    // The number of local degrees of freedom in each variable.
    const unsigned int n_u_dofs = context.get_dof_indices(this->_flow_vars.u()).size();
    const unsigned int n_p_dofs = context.get_dof_indices(this->_press_var.p()).size();

    // We get some references to cell-specific data that
    // will be used to assemble the linear system.

    // Element Jacobian * quadrature weights for interior integration.
    const std::vector<libMesh::Real> &JxW =
      context.get_element_fe(this->_flow_vars.u())->get_JxW();

    // The velocity shape function gradients (in global coords.)
    // at interior quadrature points.
    const std::vector<std::vector<libMesh::RealGradient> >& u_gradphi =
      context.get_element_fe(this->_flow_vars.u())->get_dphi();

    // The velocity shape function gradients (in global coords.)
    // at interior quadrature points.
    const std::vector<std::vector<libMesh::Real> >& u_phi =
      context.get_element_fe(this->_flow_vars.u())->get_phi();

    // The pressure shape functions at interior quadrature points.
    const std::vector<std::vector<libMesh::Real> >& p_phi =
      context.get_element_fe(this->_press_var.p())->get_phi();

    const std::vector<libMesh::Point>& u_qpoint =
      context.get_element_fe(this->_flow_vars.u())->get_xyz();

    // The subvectors and submatrices we need to fill:
    //
    // Kpu, Kpv, Kpw, Fp

    libMesh::DenseSubMatrix<libMesh::Number> &Kpu = context.get_elem_jacobian(this->_press_var.p(), this->_flow_vars.u()); // R_{p},{u}
    libMesh::DenseSubMatrix<libMesh::Number> &Kpv = context.get_elem_jacobian(this->_press_var.p(), this->_flow_vars.v()); // R_{p},{v}
    libMesh::DenseSubMatrix<libMesh::Number>* Kpw = NULL;

    libMesh::DenseSubVector<libMesh::Number> &Fp = context.get_elem_residual(this->_press_var.p()); // R_{p}

    if( this->_dim == 3 )
      {
        Kpw = &context.get_elem_jacobian(this->_press_var.p(), this->_flow_vars.w()); // R_{p},{w}
      }

    // Add the constraint given by the continuity equation.
    unsigned int n_qpoints = context.get_element_qrule().n_points();
    for (unsigned int qp=0; qp != n_qpoints; qp++)
      {
        // Compute the velocity gradient at the old Newton iterate.
        libMesh::Gradient grad_u, grad_v, grad_w;
        grad_u = context.interior_gradient(this->_flow_vars.u(), qp);
        grad_v = context.interior_gradient(this->_flow_vars.v(), qp);
        if (this->_dim == 3)
          grad_w = context.interior_gradient(this->_flow_vars.w(), qp);

        libMesh::Number divU = grad_u(0) + grad_v(1);
        if (this->_dim == 3)
          divU += grad_w(2);

        const libMesh::Number r = u_qpoint[qp](0);

        libMesh::Real jac = JxW[qp];

        if(Physics::is_axisymmetric())
          {
            libMesh::Number u = context.interior_value( this->_flow_vars.u(), qp );
            divU += u/r;
            jac *= r;
          }

        // Now a loop over the pressure degrees of freedom.  This
        // computes the contributions of the continuity equation.
        for (unsigned int i=0; i != n_p_dofs; i++)
          {
            Fp(i) += p_phi[i][qp]*divU*jac;

            if (compute_jacobian)
              {
                libmesh_assert_equal_to (context.get_elem_solution_derivative(), 1.0);

                for (unsigned int j=0; j != n_u_dofs; j++)
                  {
                    Kpu(i,j) += p_phi[i][qp]*u_gradphi[j][qp](0)*jac * context.get_elem_solution_derivative();
                    Kpv(i,j) += p_phi[i][qp]*u_gradphi[j][qp](1)*jac * context.get_elem_solution_derivative();
                    if (this->_dim == 3)
                      (*Kpw)(i,j) += p_phi[i][qp]*u_gradphi[j][qp](2)*jac * context.get_elem_solution_derivative();

                    if(Physics::is_axisymmetric())
                      {
                        Kpu(i,j) += p_phi[i][qp]*u_phi[j][qp]/r*jac * context.get_elem_solution_derivative();
                      }
                  } // end of the inner dof (j) loop

              } // end - if (compute_jacobian)

          } // end of the outer dof (i) loop
      } // end of the quadrature point (qp) loop

    // Pin p = p_value at p_point
    if( _pin_pressure )
      {
        _p_pinning.pin_value( context, compute_jacobian, this->_press_var.p() );
      }

#ifdef GRINS_USE_GRVY_TIMERS
    this->_timer->EndTimer("IncompressibleNavierStokes::element_constraint");
#endif

    return;
  }

template<class Mu >

void GRINS::IncompressibleNavierStokes< Mu >::element_time_derivative ( bool  compute_jacobian, AssemblyContext &  context, CachedValues &  cache  )

virtual

Time dependent part(s) of physics for element interiors.

Todo:

Would it be better to put this in its own DoF loop and do the if check once?

Reimplemented from GRINS::Physics.

Definition at line 94 of file inc_navier_stokes.C.

References GRINS::Physics::is_axisymmetric().

  {
#ifdef GRINS_USE_GRVY_TIMERS
    this->_timer->BeginTimer("IncompressibleNavierStokes::element_time_derivative");
#endif

    // The number of local degrees of freedom in each variable.
    const unsigned int n_u_dofs = context.get_dof_indices(this->_flow_vars.u()).size();
    const unsigned int n_p_dofs = context.get_dof_indices(this->_press_var.p()).size();

    // Check number of dofs is same for this->_flow_vars.u(), v_var and w_var.
    libmesh_assert (n_u_dofs == context.get_dof_indices(this->_flow_vars.v()).size());
    if (this->_dim == 3)
      libmesh_assert (n_u_dofs == context.get_dof_indices(this->_flow_vars.w()).size());

    // We get some references to cell-specific data that
    // will be used to assemble the linear system.

    // Element Jacobian * quadrature weights for interior integration.
    const std::vector<libMesh::Real> &JxW =
      context.get_element_fe(this->_flow_vars.u())->get_JxW();

    // The velocity shape functions at interior quadrature points.
    const std::vector<std::vector<libMesh::Real> >& u_phi =
      context.get_element_fe(this->_flow_vars.u())->get_phi();

    // The velocity shape function gradients (in global coords.)
    // at interior quadrature points.
    const std::vector<std::vector<libMesh::RealGradient> >& u_gradphi =
      context.get_element_fe(this->_flow_vars.u())->get_dphi();

    // The pressure shape functions at interior quadrature points.
    const std::vector<std::vector<libMesh::Real> >& p_phi =
      context.get_element_fe(this->_press_var.p())->get_phi();

    const std::vector<libMesh::Point>& u_qpoint =
      context.get_element_fe(this->_flow_vars.u())->get_xyz();

    // The subvectors and submatrices we need to fill:
    //
    // K_{\alpha \beta} = R_{\alpha},{\beta} = \partial{ R_{\alpha} } / \partial{ {\beta} } (where R denotes residual)
    // e.g., for \alpha = v and \beta = u we get: K{vu} = R_{v},{u}
    // Note that Kpu, Kpv, Kpw and Fp comes as constraint.

    libMesh::DenseSubMatrix<libMesh::Number> &Kuu = context.get_elem_jacobian(this->_flow_vars.u(), this->_flow_vars.u()); // R_{u},{u}
    libMesh::DenseSubMatrix<libMesh::Number> &Kuv = context.get_elem_jacobian(this->_flow_vars.u(), this->_flow_vars.v()); // R_{u},{v}
    libMesh::DenseSubMatrix<libMesh::Number>* Kuw = NULL;

    libMesh::DenseSubMatrix<libMesh::Number> &Kvu = context.get_elem_jacobian(this->_flow_vars.v(), this->_flow_vars.u()); // R_{v},{u}
    libMesh::DenseSubMatrix<libMesh::Number> &Kvv = context.get_elem_jacobian(this->_flow_vars.v(), this->_flow_vars.v()); // R_{v},{v}
    libMesh::DenseSubMatrix<libMesh::Number>* Kvw = NULL;

    libMesh::DenseSubMatrix<libMesh::Number>* Kwu = NULL;
    libMesh::DenseSubMatrix<libMesh::Number>* Kwv = NULL;
    libMesh::DenseSubMatrix<libMesh::Number>* Kww = NULL;

    libMesh::DenseSubMatrix<libMesh::Number> &Kup = context.get_elem_jacobian(this->_flow_vars.u(), this->_press_var.p()); // R_{u},{p}
    libMesh::DenseSubMatrix<libMesh::Number> &Kvp = context.get_elem_jacobian(this->_flow_vars.v(), this->_press_var.p()); // R_{v},{p}
    libMesh::DenseSubMatrix<libMesh::Number>* Kwp = NULL;

    libMesh::DenseSubVector<libMesh::Number> &Fu = context.get_elem_residual(this->_flow_vars.u()); // R_{u}
    libMesh::DenseSubVector<libMesh::Number> &Fv = context.get_elem_residual(this->_flow_vars.v()); // R_{v}
    libMesh::DenseSubVector<libMesh::Number>* Fw = NULL;

    if( this->_dim == 3 )
      {
        Kuw = &context.get_elem_jacobian(this->_flow_vars.u(), this->_flow_vars.w()); // R_{u},{w}
        Kvw = &context.get_elem_jacobian(this->_flow_vars.v(), this->_flow_vars.w()); // R_{v},{w}
        Kwu = &context.get_elem_jacobian(this->_flow_vars.w(), this->_flow_vars.u()); // R_{w},{u};
        Kwv = &context.get_elem_jacobian(this->_flow_vars.w(), this->_flow_vars.v()); // R_{w},{v};
        Kww = &context.get_elem_jacobian(this->_flow_vars.w(), this->_flow_vars.w()); // R_{w},{w}
        Kwp = &context.get_elem_jacobian(this->_flow_vars.w(), this->_press_var.p()); // R_{w},{p}
        Fw  = &context.get_elem_residual(this->_flow_vars.w()); // R_{w}
      }

    // Now we will build the element Jacobian and residual.
    // Constructing the residual requires the solution and its
    // gradient from the previous timestep.  This must be
    // calculated at each quadrature point by summing the
    // solution degree-of-freedom values by the appropriate
    // weight functions.
    unsigned int n_qpoints = context.get_element_qrule().n_points();

    for (unsigned int qp=0; qp != n_qpoints; qp++)
      {
        // Compute the solution & its gradient at the old Newton iterate.
        libMesh::Number p, u, v;
        p = context.interior_value(this->_press_var.p(), qp);
        u = context.interior_value(this->_flow_vars.u(), qp);
        v = context.interior_value(this->_flow_vars.v(), qp);

        libMesh::Gradient grad_u, grad_v, grad_w;
        grad_u = context.interior_gradient(this->_flow_vars.u(), qp);
        grad_v = context.interior_gradient(this->_flow_vars.v(), qp);
        if (this->_dim == 3)
          grad_w = context.interior_gradient(this->_flow_vars.w(), qp);

        libMesh::NumberVectorValue U(u,v);
        if (this->_dim == 3)
          U(2) = context.interior_value(this->_flow_vars.w(), qp); // w

        const libMesh::Number  grad_u_x = grad_u(0);
        const libMesh::Number  grad_u_y = grad_u(1);
        const libMesh::Number  grad_u_z = (this->_dim == 3)?grad_u(2):0;
        const libMesh::Number  grad_v_x = grad_v(0);
        const libMesh::Number  grad_v_y = grad_v(1);
        const libMesh::Number  grad_v_z = (this->_dim == 3)?grad_v(2):0;
        const libMesh::Number  grad_w_x = (this->_dim == 3)?grad_w(0):0;
        const libMesh::Number  grad_w_y = (this->_dim == 3)?grad_w(1):0;
        const libMesh::Number  grad_w_z = (this->_dim == 3)?grad_w(2):0;

        const libMesh::Number r = u_qpoint[qp](0);

        libMesh::Real jac = JxW[qp];

        // Compute the viscosity at this qp
        libMesh::Real _mu_qp = this->_mu(context, qp);

        if(Physics::is_axisymmetric())
          {
            jac *= r;
          }

        // First, an i-loop over the velocity degrees of freedom.
        // We know that n_u_dofs == n_v_dofs so we can compute contributions
        // for both at the same time.
        for (unsigned int i=0; i != n_u_dofs; i++)
          {
            Fu(i) += jac *
              (-this->_rho*u_phi[i][qp]*(U*grad_u)        // convection term
               +p*u_gradphi[i][qp](0)              // pressure term
               -_mu_qp*(u_gradphi[i][qp]*grad_u) ); // diffusion term

            if(Physics::is_axisymmetric())
              {
                Fu(i) += u_phi[i][qp]*( p/r - _mu_qp*U(0)/(r*r) )*jac;
              }

            Fv(i) += jac *
              (-this->_rho*u_phi[i][qp]*(U*grad_v)        // convection term
               +p*u_gradphi[i][qp](1)              // pressure term
               -_mu_qp*(u_gradphi[i][qp]*grad_v) ); // diffusion term

            if (this->_dim == 3)
              {
                (*Fw)(i) += jac *
                  (-this->_rho*u_phi[i][qp]*(U*grad_w)        // convection term
                   +p*u_gradphi[i][qp](2)              // pressure term
                   -_mu_qp*(u_gradphi[i][qp]*grad_w) ); // diffusion term
              }

            if (compute_jacobian)
              {
                for (unsigned int j=0; j != n_u_dofs; j++)
                  {
                    // TODO: precompute some terms like:
                    //   (Uvec*u_gradphi[j][qp]),
                    //   u_phi[i][qp]*u_phi[j][qp],
                    //   (u_gradphi[i][qp]*u_gradphi[j][qp])

                    Kuu(i,j) += jac * context.get_elem_solution_derivative() *
                      (-this->_rho*u_phi[i][qp]*(U*u_gradphi[j][qp])       // convection term
                       -this->_rho*u_phi[i][qp]*grad_u_x*u_phi[j][qp]             // convection term
                       -_mu_qp*(u_gradphi[i][qp]*u_gradphi[j][qp])); // diffusion term


                    if(Physics::is_axisymmetric())
                      {
                        Kuu(i,j) -= u_phi[i][qp]*_mu_qp*u_phi[j][qp]/(r*r)*jac * context.get_elem_solution_derivative();
                      }

                    Kuv(i,j) += jac * context.get_elem_solution_derivative() *
                      (-this->_rho*u_phi[i][qp]*grad_u_y*u_phi[j][qp]);           // convection term

                    Kvv(i,j) += jac * context.get_elem_solution_derivative() *
                      (-this->_rho*u_phi[i][qp]*(U*u_gradphi[j][qp])       // convection term
                       -this->_rho*u_phi[i][qp]*grad_v_y*u_phi[j][qp]             // convection term
                       -_mu_qp*(u_gradphi[i][qp]*u_gradphi[j][qp])); // diffusion term

                    Kvu(i,j) += jac * context.get_elem_solution_derivative() *
                      (-this->_rho*u_phi[i][qp]*grad_v_x*u_phi[j][qp]);           // convection term

                    if (this->_dim == 3)
                      {
                        (*Kuw)(i,j) += jac * context.get_elem_solution_derivative() *
                          (-this->_rho*u_phi[i][qp]*grad_u_z*u_phi[j][qp]);           // convection term

                        (*Kvw)(i,j) += jac * context.get_elem_solution_derivative() *
                          (-this->_rho*u_phi[i][qp]*grad_v_z*u_phi[j][qp]);           // convection term

                        (*Kww)(i,j) += jac * context.get_elem_solution_derivative() *
                          (-this->_rho*u_phi[i][qp]*(U*u_gradphi[j][qp])       // convection term
                           -this->_rho*u_phi[i][qp]*grad_w_z*u_phi[j][qp]             // convection term
                           -_mu_qp*(u_gradphi[i][qp]*u_gradphi[j][qp])); // diffusion term
                        (*Kwu)(i,j) += jac * context.get_elem_solution_derivative() *
                          (-this->_rho*u_phi[i][qp]*grad_w_x*u_phi[j][qp]);           // convection term
                        (*Kwv)(i,j) += jac * context.get_elem_solution_derivative() *
                          (-this->_rho*u_phi[i][qp]*grad_w_y*u_phi[j][qp]);           // convection term
                      }
                  } // end of the inner dof (j) loop

                // Matrix contributions for the up, vp and wp couplings
                for (unsigned int j=0; j != n_p_dofs; j++)
                  {
                    Kup(i,j) += u_gradphi[i][qp](0)*p_phi[j][qp]*jac * context.get_elem_solution_derivative();
                    Kvp(i,j) += u_gradphi[i][qp](1)*p_phi[j][qp]*jac * context.get_elem_solution_derivative();

                    if (this->_dim == 3)
                      {
                        (*Kwp)(i,j) += u_gradphi[i][qp](2)*p_phi[j][qp]*jac * context.get_elem_solution_derivative();
                      }

                    if(Physics::is_axisymmetric())
                      {
                        Kup(i,j) += u_phi[i][qp]*p_phi[j][qp]/r*jac * context.get_elem_solution_derivative();
                      }

                  } // end of the inner dof (j) loop



              } // end - if (compute_jacobian)

          } // end of the outer dof (i) loop
      } // end of the quadrature point (qp) loop

#ifdef GRINS_USE_GRVY_TIMERS
    this->_timer->EndTimer("IncompressibleNavierStokes::element_time_derivative");
#endif

    return;
  }

template<class Mu >

void GRINS::IncompressibleNavierStokes< Mu >::mass_residual ( bool  compute_jacobian, AssemblyContext &  context, CachedValues &  cache  )

virtual

Mass matrix part(s) for element interiors. All boundary terms lie within the time_derivative part.

Reimplemented from GRINS::Physics.

Definition at line 450 of file inc_navier_stokes.C.

References GRINS::Physics::is_axisymmetric().

  {
    // Element Jacobian * quadrature weights for interior integration
    // We assume the same for each flow variable
    const std::vector<libMesh::Real> &JxW =
      context.get_element_fe(this->_flow_vars.u())->get_JxW();

    // The shape functions at interior quadrature points.
    // We assume the same for each flow variable
    const std::vector<std::vector<libMesh::Real> >& u_phi =
      context.get_element_fe(this->_flow_vars.u())->get_phi();

    const std::vector<libMesh::Point>& u_qpoint =
      context.get_element_fe(this->_flow_vars.u())->get_xyz();

    // The number of local degrees of freedom in each variable
    const unsigned int n_u_dofs = context.get_dof_indices(this->_flow_vars.u()).size();

    // The subvectors and submatrices we need to fill:
    libMesh::DenseSubVector<libMesh::Real> &F_u = context.get_elem_residual(this->_flow_vars.u());
    libMesh::DenseSubVector<libMesh::Real> &F_v = context.get_elem_residual(this->_flow_vars.v());
    libMesh::DenseSubVector<libMesh::Real>* F_w = NULL;

    libMesh::DenseSubMatrix<libMesh::Real> &M_uu = context.get_elem_jacobian(this->_flow_vars.u(), this->_flow_vars.u());
    libMesh::DenseSubMatrix<libMesh::Real> &M_vv = context.get_elem_jacobian(this->_flow_vars.v(), this->_flow_vars.v());
    libMesh::DenseSubMatrix<libMesh::Real>* M_ww = NULL;

    if( this->_dim == 3 )
      {
        F_w  = &context.get_elem_residual(this->_flow_vars.w()); // R_{w}
        M_ww = &context.get_elem_jacobian(this->_flow_vars.w(), this->_flow_vars.w());
      }

    unsigned int n_qpoints = context.get_element_qrule().n_points();

    for (unsigned int qp = 0; qp != n_qpoints; ++qp)
      {
        // For the mass residual, we need to be a little careful.
        // The time integrator is handling the time-discretization
        // for us so we need to supply M(u_fixed)*u' for the residual.
        // u_fixed will be given by the fixed_interior_value function
        // while u' will be given by the interior_rate function.
        libMesh::Real u_dot, v_dot, w_dot = 0.0;
        context.interior_rate(this->_flow_vars.u(), qp, u_dot);
        context.interior_rate(this->_flow_vars.v(), qp, v_dot);

        if(this->_dim == 3 )
          context.interior_rate(this->_flow_vars.w(), qp, w_dot);

        const libMesh::Number r = u_qpoint[qp](0);

        libMesh::Real jac = JxW[qp];

        if(Physics::is_axisymmetric())
          {
            jac *= r;
          }

        for (unsigned int i = 0; i != n_u_dofs; ++i)
          {
            F_u(i) -= this->_rho*u_dot*u_phi[i][qp]*jac;
            F_v(i) -= this->_rho*v_dot*u_phi[i][qp]*jac;

            if( this->_dim == 3 )
              (*F_w)(i) -= this->_rho*w_dot*u_phi[i][qp]*jac;

            if( compute_jacobian )
              {
                for (unsigned int j=0; j != n_u_dofs; j++)
                  {
                    // Assuming rho is constant w.r.t. u, v, w
                    // and T (if Boussinesq added).
                    libMesh::Real value = this->_rho*u_phi[i][qp]*u_phi[j][qp]*jac * context.get_elem_solution_rate_derivative();

                    M_uu(i,j) -= value;
                    M_vv(i,j) -= value;

                    if( this->_dim == 3)
                      {
                        (*M_ww)(i,j) -= value;
                      }

                  } // End dof loop
              } // End Jacobian check
          } // End dof loop
      } // End quadrature loop

    return;
  }

template<class Mu >

void GRINS::IncompressibleNavierStokes< Mu >::register_postprocessing_vars ( const GetPot &  input, PostProcessedQuantities< libMesh::Real > &  postprocessing  )

virtual

Register postprocessing variables for IncompressibleNavierStokes.

Reimplemented from GRINS::Physics.

Definition at line 63 of file inc_navier_stokes.C.

References GRINS::PhysicsNaming::incompressible_navier_stokes(), and GRINS::PostProcessedQuantities< NumericType >::register_quantity().

  {
    std::string section = "Physics/"+PhysicsNaming::incompressible_navier_stokes()+"/output_vars";

    if( input.have_variable(section) )
      {
        unsigned int n_vars = input.vector_variable_size(section);

        for( unsigned int v = 0; v < n_vars; v++ )
          {
            std::string name = input(section,"DIE!",v);

            if( name == std::string("mu") )
              {
                this->_mu_index = postprocessing.register_quantity( name );
              }
            else
              {
                std::cerr << "Error: Invalid output_vars value for "+PhysicsNaming::incompressible_navier_stokes() << std::endl
                          << "       Found " << name << std::endl
                          << "       Acceptable values are: mu" << std::endl;
                libmesh_error();
              }
          }
      }

    return;
  }

Member Data Documentation

template<class Viscosity >

unsigned int GRINS::IncompressibleNavierStokes< Viscosity >::_mu_index

protected

Index from registering this quantity.

Definition at line 90 of file inc_navier_stokes.h.

template<class Viscosity >

PressurePinning GRINS::IncompressibleNavierStokes< Viscosity >::_p_pinning

protected

Definition at line 84 of file inc_navier_stokes.h.

template<class Viscosity >

bool GRINS::IncompressibleNavierStokes< Viscosity >::_pin_pressure

protected

Enable pressure pinning.

Definition at line 87 of file inc_navier_stokes.h.

Referenced by GRINS::IncompressibleNavierStokes< Viscosity >::IncompressibleNavierStokes().

---

The documentation for this class was generated from the following files:

• src/physics/include/grins/inc_navier_stokes.h
• src/physics/src/inc_navier_stokes.C