linearised_navier_stokes_eigenvalue_elements.h

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//LIC// ====================================================================
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//LIC//    Version 1.0; svn revision $LastChangedRevision: 1097 $
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//LIC// $LastChangedDate: 2015-12-17 11:53:17 +0000 (Thu, 17 Dec 2015) $
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//LIC// Copyright (C) 2006-2016 Matthias Heil and Andrew Hazel
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//LIC//====================================================================
// Header file for elements that allow the imposition of a "constant volume"
// constraint in free surface problems.

//Include guards, to prevent multiple includes
#ifndef LINEARISED_NAVIER_STOKES_EIGENVALUE_ELEMENTS_HEADER
#define LINEARISED_NAVIER_STOKES_EIGENVALUE_ELEMENTS_HEADER


// Config header generated by autoconfig
#ifdef HAVE_CONFIG_H
  #include <oomph-lib-config.h>
#endif

//OOMPH-LIB headers
#include "../generic/elements.h"


namespace oomph
{

//==========================================================================
/// A class that is used to implement the constraint that the eigenfunction
/// has a particular normalisation. This element stores the two components
/// of the eigenvalue.
//=========================================================================
 class LinearisedNavierStokesEigenfunctionNormalisationElement : public GeneralisedElement
 {
   private:
  
  /// Pointer to the desired normalisation
  std::complex<double> *Normalisation_pt;

  ///Storage for the initial index of the eigenvalue
  unsigned External_or_internal_data_index_of_eigenvalue;

  ///Storage for the offset index of the eigenvalue
  unsigned Index_of_eigenvalue;
  
  
  /// \short The local eqn number for the traded pressure
  inline int eigenvalue_local_eqn(const unsigned &i)
  {
   return this->internal_local_eqn(
    External_or_internal_data_index_of_eigenvalue,
    Index_of_eigenvalue+i);
  }
    
  /// \short Fill in the residuals for the volume constraint
 void fill_in_generic_contribution_to_residuals_normalisation(
  Vector<double> &residuals);
  
   public:
 
 /// \short Constructor: Pass pointer to target volume. "Pressure" value that
 /// "traded" for the volume contraint is created internally (as a Data
 /// item with a single pressure value)
 LinearisedNavierStokesEigenfunctionNormalisationElement(
  std::complex<double>* const &normalisation_pt);
 
 /// \short Constructor: Pass pointer to target volume, pointer to Data
 /// item whose value specified by index_of_traded_pressure represents
 /// the "Pressure" value that "traded" for the volume contraint.
 /// The Data is stored as external Data for this element.
 /*LinearisedNavierStokesEigenfunctionNormalisationElement(double* prescribed_volume_pt,
                                   Data* p_traded_data_pt,
                                   const unsigned& index_of_traded_pressure);*/
 
 /// \short Empty destructor
 ~LinearisedNavierStokesEigenfunctionNormalisationElement() {}

 /// Access to Data that contains the traded pressure
 inline Data* eigenvalue_data_pt()
 {
  return internal_data_pt(
   External_or_internal_data_index_of_eigenvalue);
 }

 /// Return the traded pressure value
 inline double eigenvalue(const unsigned &i)
 {return eigenvalue_data_pt()->value(Index_of_eigenvalue+i);}
 
 /// Return the index of Data object  at which the traded pressure is stored
 inline unsigned index_of_eigenvalue() {return Index_of_eigenvalue;}
 
 
 /// \short Fill in the residuals for the volume constraint
 void fill_in_contribution_to_residuals( Vector<double> &residuals)
 {
  this->fill_in_generic_contribution_to_residuals_normalisation(
   residuals);
 }
  
 /// \short Fill in the residuals and jacobian for the volume constraint
 void fill_in_contribution_to_jacobian(Vector<double> &residuals,
                                       DenseMatrix<double> &jacobian)
 {
  //One contribution to jacobian; see comment in that function
  this->fill_in_generic_contribution_to_residuals_normalisation(
   residuals);

  const int local_eqn = this->eigenvalue_local_eqn(2);
  if(local_eqn >= 0)
   {
    const int local_unknown = this->eigenvalue_local_eqn(0);
    jacobian(local_eqn,local_unknown) += 1.0;
   }
 }
 
 /// \short Fill in the residuals, jacobian and mass matrix for the volume
 /// constraint.
 void fill_in_contribution_to_jacobian_and_mass_matrix(
  Vector<double> &residuals,
  DenseMatrix<double> &jacobian,
  DenseMatrix<double> &mass_matrix)
 {
  //No contribution to jacobian or mass matrix; see comment in that function
  this->fill_in_generic_contribution_to_residuals_normalisation(
   residuals);
 }

}; 

}
#endif