Line data    Source code

       1             : // The libMesh Finite Element Library.
       2             : // Copyright (C) 2002-2025 Benjamin S. Kirk, John W. Peterson, Roy H. Stogner
       3             : 
       4             : // This library is free software; you can redistribute it and/or
       5             : // modify it under the terms of the GNU Lesser General Public
       6             : // License as published by the Free Software Foundation; either
       7             : // version 2.1 of the License, or (at your option) any later version.
       8             : 
       9             : // This library is distributed in the hope that it will be useful,
      10             : // but WITHOUT ANY WARRANTY; without even the implied warranty of
      11             : // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12             : // Lesser General Public License for more details.
      13             : 
      14             : // You should have received a copy of the GNU Lesser General Public
      15             : // License along with this library; if not, write to the Free Software
      16             : // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
      17             : 
      18             : 
      19             : 
      20             : #ifndef LIBMESH_FEM_PHYSICS_H
      21             : #define LIBMESH_FEM_PHYSICS_H
      22             : 
      23             : // Local Includes
      24             : #include "libmesh/libmesh.h" // for libMesh::invalid_uint
      25             : #include "libmesh/diff_physics.h"
      26             : 
      27             : // C++ includes
      28             : 
      29             : namespace libMesh
      30             : {
      31             : 
      32             : /**
      33             :  * This class provides a specific system class.  It aims
      34             :  * to generalize any system, linear or nonlinear, which
      35             :  * provides both a residual and a Jacobian.
      36             :  *
      37             :  * This class is part of the new DifferentiableSystem framework,
      38             :  * which is still experimental.  Users of this framework should
      39             :  * beware of bugs and future API changes.
      40             :  *
      41             :  * \author Roy H. Stogner
      42             :  * \date 2012
      43             :  */
      44             : class FEMPhysics : public virtual DifferentiablePhysics
      45             : {
      46             : public:
      47             : 
      48             :   /**
      49             :    * Constructor.
      50             :    */
      51         134 :   FEMPhysics () :
      52        5028 :     DifferentiablePhysics()
      53         134 :   {}
      54             : 
      55             :   /**
      56             :    * Destructor.
      57             :    */
      58        5028 :   virtual ~FEMPhysics () = default;
      59             : 
      60             :   /**
      61             :    * Adds a pseudo-convection contribution on \p elem to
      62             :    * elem_residual, if the nodes of \p elem are being translated by a
      63             :    * moving mesh.
      64             :    *
      65             :    * This function assumes that the user's time derivative equations
      66             :    * (except for any equations involving unknown mesh xyz coordinates
      67             :    * themselves) are expressed in an Eulerian frame of reference, and
      68             :    * that the user is satisfied with an unstabilized convection term.
      69             :    * Lagrangian equations will probably require overriding
      70             :    * eulerian_residual() with a blank function; ALE or stabilized
      71             :    * formulations will require reimplementing eulerian_residual()
      72             :    * entirely.
      73             :    */
      74             :   virtual bool eulerian_residual (bool request_jacobian,
      75             :                                   DiffContext & context) override;
      76             : 
      77             :   /**
      78             :    * Subtracts a mass vector contribution on \p elem from
      79             :    * elem_residual.
      80             :    *
      81             :    * If this method receives request_jacobian = true, then it
      82             :    * should compute elem_jacobian and return true if possible.  If
      83             :    * elem_jacobian has not been computed then the method should
      84             :    * return false.
      85             :    *
      86             :    * Many problems can use the reimplementation in
      87             :    * FEMPhysics::mass_residual which subtracts (du/dt,v) for each
      88             :    * transient variable u; users with more complicated transient
      89             :    * problems will need to reimplement this themselves.
      90             :    */
      91             :   virtual bool mass_residual (bool request_jacobian,
      92             :                               DiffContext &) override;
      93             : };
      94             : 
      95             : 
      96             : 
      97             : } // namespace libMesh
      98             : 
      99             : 
     100             : #endif // LIBMESH_FEM_PHYSICS_H