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_TWOSTEP_TIME_SOLVER_H
      21             : #define LIBMESH_TWOSTEP_TIME_SOLVER_H
      22             : 
      23             : // Local includes
      24             : #include "libmesh/adaptive_time_solver.h"
      25             : 
      26             : // C++ includes
      27             : 
      28             : namespace libMesh
      29             : {
      30             : 
      31             : // Forward declarations
      32             : class System;
      33             : 
      34             : // UPDATE THIS DESCRIPTION
      35             : 
      36             : /**
      37             :  * This class wraps another UnsteadySolver derived class, and compares
      38             :  * the results of timestepping with deltat and timestepping with
      39             :  * 2*deltat to adjust future timestep lengths.
      40             :  *
      41             :  * Currently this class only works on fully coupled Systems
      42             :  *
      43             :  * This class is part of the new DifferentiableSystem framework,
      44             :  * which is still experimental.  Users of this framework should
      45             :  * beware of bugs and future API changes.
      46             :  *
      47             :  * \author Roy H. Stogner
      48             :  * \date 2007
      49             :  */
      50          48 : class TwostepTimeSolver : public AdaptiveTimeSolver
      51             : {
      52             : public:
      53             :   /**
      54             :    * The parent class
      55             :    */
      56             :   typedef AdaptiveTimeSolver Parent;
      57             : 
      58             :   /**
      59             :    * Constructor. Requires a reference to the system
      60             :    * to be solved.
      61             :    */
      62             :   explicit
      63             :   TwostepTimeSolver (sys_type & s);
      64             : 
      65             :   /**
      66             :    * Destructor.
      67             :    */
      68             :   ~TwostepTimeSolver ();
      69             : 
      70             :   virtual void solve() override;
      71             : 
      72             :   virtual std::pair<unsigned int, Real> adjoint_solve (const QoISet & qoi_indices) override;
      73             : 
      74             :   /**
      75             :    * A method to integrate the system::QoI functionals.
      76             :    */
      77             :   virtual void integrate_qoi_timestep() override;
      78             : 
      79             :   /**
      80             :    * A method to integrate the adjoint sensitivity w.r.t a given parameter
      81             :    * vector. int_{tstep_start}^{tstep_end} dQ/dp dt = int_{tstep_start}^{tstep_end} (\partialQ / \partial p) - ( \partial R (u,z) / \partial p ) dt
      82             :    * The midpoint rule is used to integrate each substep
      83             :    */
      84             :   virtual void integrate_adjoint_sensitivity(const QoISet & qois, const ParameterVector & parameter_vector, SensitivityData & sensitivities) override;
      85             : 
      86             : #ifdef LIBMESH_ENABLE_AMR
      87             :   /**
      88             :    * A method to compute the adjoint refinement error estimate at the current timestep.
      89             :    * int_{tstep_start}^{tstep_end} R(u^h,z) dt
      90             :    * The user provides an initialized ARefEE object.
      91             :    * Fills in an ErrorVector that contains the weighted sum of errors from all the QoIs and can be used to guide AMR.
      92             :    * CURRENTLY ONLY SUPPORTED for Backward Euler.
      93             :    */
      94             :   virtual void integrate_adjoint_refinement_error_estimate(AdjointRefinementEstimator & adjoint_refinement_error_estimator, ErrorVector & QoI_elementwise_error) override;
      95             : #endif // LIBMESH_ENABLE_AMR
      96             : 
      97             : };
      98             : 
      99             : 
     100             : } // namespace libMesh
     101             : 
     102             : 
     103             : #endif // LIBMESH_TWOSTEP_TIME_SOLVER_H