adaptive_driven_cavity.cc

Go to the documentation of this file.

//LIC// ====================================================================
//LIC// This file forms part of oomph-lib, the object-oriented, 
//LIC// multi-physics finite-element library, available 
//LIC// at http://www.oomph-lib.org.
//LIC// 
//LIC// Copyright (C) 2006-2025 Matthias Heil and Andrew Hazel
//LIC// 
//LIC// This library is free software; you can redistribute it and/or
//LIC// modify it under the terms of the GNU Lesser General Public
//LIC// License as published by the Free Software Foundation; either
//LIC// version 2.1 of the License, or (at your option) any later version.
//LIC// 
//LIC// This library is distributed in the hope that it will be useful,
//LIC// but WITHOUT ANY WARRANTY; without even the implied warranty of
//LIC// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
//LIC// Lesser General Public License for more details.
//LIC// 
//LIC// You should have received a copy of the GNU Lesser General Public
//LIC// License along with this library; if not, write to the Free Software
//LIC// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
//LIC// 02110-1301  USA.
//LIC// 
//LIC// The authors may be contacted at oomph-lib@maths.man.ac.uk.
//LIC// 
//LIC//====================================================================
// Driver for adaptive 2D rectangular driven cavity. Solved with black
// box adaptation, using Taylor Hood and Crouzeix Raviart elements.
 
// Generic oomph-lib header
#include "generic.h"
 
// Navier Stokes headers
#include "navier_stokes.h"
 
// The mesh
#include "meshes/rectangular_quadmesh.h"
 
using namespace std;
 
using namespace oomph;
 
//==start_of_namespace===================================================
/// Namespace for physical parameters
//=======================================================================
namespace Global_Physical_Variables
{
 /// Reynolds number
 double Re=100;
} // end_of_namespace
 
 
 
//==start_of_problem_class============================================
/// Driven cavity problem in rectangular domain, templated
/// by element type. 
//====================================================================
template<class ELEMENT>
class RefineableDrivenCavityProblem : public Problem
{
 
public:
 
 /// Constructor
 RefineableDrivenCavityProblem();
 
 /// Destructor: Empty
 ~RefineableDrivenCavityProblem() {}
 
 /// Update the after solve (empty)
 void actions_after_newton_solve() {}
 
 /// Update the problem specs before solve. 
 /// (Re-)set velocity boundary conditions just to be on the safe side...
 void actions_before_newton_solve()
  { 
  // Setup tangential flow along boundary 0:
  unsigned ibound=0; 
  unsigned num_nod= mesh_pt()->nboundary_node(ibound);
  for (unsigned inod=0;inod<num_nod;inod++)
   {
    // Tangential flow
    unsigned i=0;
    mesh_pt()->boundary_node_pt(ibound,inod)->set_value(i,1.0);
    // No penetration
    i=1;
    mesh_pt()->boundary_node_pt(ibound,inod)->set_value(i,0.0);
   }
  
  // Overwrite with no flow along all other boundaries
  unsigned num_bound = mesh_pt()->nboundary();
  for(unsigned ibound=1;ibound<num_bound;ibound++)
   {
    unsigned num_nod= mesh_pt()->nboundary_node(ibound);
    for (unsigned inod=0;inod<num_nod;inod++)
     {
      for (unsigned i=0;i<2;i++)
       {
        mesh_pt()->boundary_node_pt(ibound,inod)->set_value(i,0.0);
       }
     }
   }
  } // end_of_actions_before_newton_solve
 
 
 /// After adaptation: Unpin pressure and pin redudant pressure dofs.
 void actions_after_adapt()
  {
   // Unpin all pressure dofs
   RefineableNavierStokesEquations<2>::
    unpin_all_pressure_dofs(mesh_pt()->element_pt());
    
    // Pin redundant pressure dofs
   RefineableNavierStokesEquations<2>::
    pin_redundant_nodal_pressures(mesh_pt()->element_pt());
   
   // Now set the first pressure dof in the first element to 0.0
   fix_pressure(0,0,0.0);
  } // end_of_actions_after_adapt
 
 /// Doc the solution
 void doc_solution(DocInfo& doc_info);
 
 
private:
 
 /// Fix pressure in element e at pressure dof pdof and set to pvalue
 void fix_pressure(const unsigned &e, const unsigned &pdof, 
                   const double &pvalue)
  {
   //Cast to proper element and fix pressure
   dynamic_cast<ELEMENT*>(mesh_pt()->element_pt(e))->
                          fix_pressure(pdof,pvalue);
  } // end_of_fix_pressure
 
}; // end_of_problem_class
 
 
 
//==start_of_constructor==================================================
/// Constructor for RefineableDrivenCavity problem 
///
//========================================================================
template<class ELEMENT>
RefineableDrivenCavityProblem<ELEMENT>::RefineableDrivenCavityProblem()
{ 
 
 // Setup mesh
 
 // # of elements in x-direction
 unsigned n_x=10;
 
 // # of elements in y-direction
 unsigned n_y=10;
 
 // Domain length in x-direction
 double l_x=1.0;
 
 // Domain length in y-direction
 double l_y=1.0;
 
 // Build and assign mesh
 Problem::mesh_pt() = 
  new RefineableRectangularQuadMesh<ELEMENT>(n_x,n_y,l_x,l_y);
 
 // Set error estimator
 Z2ErrorEstimator* error_estimator_pt=new Z2ErrorEstimator;
 dynamic_cast<RefineableRectangularQuadMesh<ELEMENT>*>(mesh_pt())->
  spatial_error_estimator_pt()=error_estimator_pt;
 
 // Set the boundary conditions for this problem: All nodes are
 // free by default -- just pin the ones that have Dirichlet conditions
 // here: All boundaries are Dirichlet boundaries.
 unsigned num_bound = mesh_pt()->nboundary();
 for(unsigned ibound=0;ibound<num_bound;ibound++)
  {
   unsigned num_nod= mesh_pt()->nboundary_node(ibound);
   for (unsigned inod=0;inod<num_nod;inod++)
    {
     // Loop over values (u and v velocities)
     for (unsigned i=0;i<2;i++)
      {
       mesh_pt()->boundary_node_pt(ibound,inod)->pin(i); 
      }
    }
  } // end loop over boundaries
 
 //Find number of elements in mesh
 unsigned n_element = mesh_pt()->nelement();
 
 // Loop over the elements to set up element-specific 
 // things that cannot be handled by constructor: Pass pointer to Reynolds
 // number
 for(unsigned e=0;e<n_element;e++)
  {
   // Upcast from GeneralisedElement to the present element
   ELEMENT* el_pt = dynamic_cast<ELEMENT*>(mesh_pt()->element_pt(e));
   //Set the Reynolds number, etc
   el_pt->re_pt() = &Global_Physical_Variables::Re;
  } // end loop over elements
 
 // Pin redudant pressure dofs
 RefineableNavierStokesEquations<2>::
  pin_redundant_nodal_pressures(mesh_pt()->element_pt());
 
  // Now set the first pressure dof in the first element to 0.0
 fix_pressure(0,0,0.0);
 
 // Setup equation numbering scheme
 cout <<"Number of equations: " << assign_eqn_numbers() << std::endl; 
 
} // end_of_constructor
 
 
 
//==start_of_doc_solution=================================================
/// Doc the solution
//========================================================================
template<class ELEMENT>
void RefineableDrivenCavityProblem<ELEMENT>::doc_solution(DocInfo& doc_info)
{ 
 
 ofstream some_file;
 char filename[100];
 
 // Number of plot points
 unsigned npts=5; 
 
 
 // Output solution 
 snprintf(filename, sizeof(filename), "%s/soln%i.dat",doc_info.directory().c_str(),
         doc_info.number());
 some_file.open(filename);
 mesh_pt()->output(some_file,npts);
 some_file.close();
 
} // end_of_doc_solution
 
 
 
 
//==start_of_main======================================================
/// Driver for RefineableDrivenCavity test problem 
//=====================================================================
int main()
{
 
 // Set output directory
 DocInfo doc_info;
 doc_info.set_directory("RESLT");
 
 
 // Set max. number of black-box adaptation
 unsigned max_adapt=3;
 
 // Solve problem with Taylor Hood elements
 //---------------------------------------
 {
  //Build problem
  RefineableDrivenCavityProblem<RefineableQTaylorHoodElement<2> > problem;
  
  // Solve the problem with automatic adaptation
  problem.newton_solve(max_adapt);
  
  // Step number
  doc_info.number()=0;
   
  //Output solution
  problem.doc_solution(doc_info);
 } // end of Taylor Hood elements
 
 
 // Solve problem with Crouzeix Raviart elements
 //--------------------------------------------
 {
  // Build problem
  RefineableDrivenCavityProblem<RefineableQCrouzeixRaviartElement<2> > problem;
  
  // Solve the problem with automatic adaptation
  problem.newton_solve(max_adapt);
  
  // Step number
  doc_info.number()=1;
 
  //Output solution
  problem.doc_solution(doc_info);
 } // end of Crouzeix Raviart elements
 
 
} // end_of_main