void UnsteadySolver::solve ()
{
if (first_solve)
{
advance_timestep();
first_solve = false;
}
unsigned int solve_result = _diff_solver->solve();
// If we requested the UnsteadySolver to attempt reducing dt after a
// failed DiffSolver solve, check the results of the solve now.
if (reduce_deltat_on_diffsolver_failure)
{
bool backtracking_failed =
solve_result & DiffSolver::DIVERGED_BACKTRACKING_FAILURE;
bool max_iterations =
solve_result & DiffSolver::DIVERGED_MAX_NONLINEAR_ITERATIONS;
if (backtracking_failed || max_iterations)
{
// Cut timestep in half
for (unsigned int nr=0; nr<reduce_deltat_on_diffsolver_failure; ++nr)
{
_system.deltat *= 0.5;
libMesh::out << "Newton backtracking failed. Trying with smaller timestep, dt="
<< _system.deltat << std::endl;
solve_result = _diff_solver->solve();
// Check solve results with reduced timestep
bool backtracking_still_failed =
solve_result & DiffSolver::DIVERGED_BACKTRACKING_FAILURE;
bool backtracking_max_iterations =
solve_result & DiffSolver::DIVERGED_MAX_NONLINEAR_ITERATIONS;
if (!backtracking_still_failed && !backtracking_max_iterations)
{
if (!quiet)
libMesh::out << "Reduced dt solve succeeded." << std::endl;
return;
}
}
// If we made it here, we still couldn't converge the solve after
// reducing deltat
libMesh::out << "DiffSolver::solve() did not succeed after "
<< reduce_deltat_on_diffsolver_failure
<< " attempts." << std::endl;
libmesh_convergence_failure();
} // end if (backtracking_failed || max_iterations)
} // end if (reduce_deltat_on_diffsolver_failure)
}
void UnsteadySolver::solve ()
{
if (first_solve)
{
advance_timestep();
first_solve = false;
}
#ifdef LIBMESH_ENABLE_GHOSTED
old_local_nonlinear_solution->init (_system.n_dofs(), _system.n_local_dofs(),
_system.get_dof_map().get_send_list(), false,
GHOSTED);
#else
old_local_nonlinear_solution->init (_system.n_dofs(), false, SERIAL);
#endif
_system.get_vector("_old_nonlinear_solution").localize
(*old_local_nonlinear_solution,
_system.get_dof_map().get_send_list());
unsigned int solve_result = _diff_solver->solve();
// If we requested the UnsteadySolver to attempt reducing dt after a
// failed DiffSolver solve, check the results of the solve now.
if (reduce_deltat_on_diffsolver_failure)
{
bool backtracking_failed =
solve_result & DiffSolver::DIVERGED_BACKTRACKING_FAILURE;
bool max_iterations =
solve_result & DiffSolver::DIVERGED_MAX_NONLINEAR_ITERATIONS;
if (backtracking_failed || max_iterations)
{
// Cut timestep in half
for (unsigned int nr=0; nr<reduce_deltat_on_diffsolver_failure; ++nr)
{
_system.deltat *= 0.5;
libMesh::out << "Newton backtracking failed. Trying with smaller timestep, dt="
<< _system.deltat << std::endl;
solve_result = _diff_solver->solve();
// Check solve results with reduced timestep
bool backtracking_failed =
solve_result & DiffSolver::DIVERGED_BACKTRACKING_FAILURE;
bool max_iterations =
solve_result & DiffSolver::DIVERGED_MAX_NONLINEAR_ITERATIONS;
if (!backtracking_failed && !max_iterations)
{
if (!quiet)
libMesh::out << "Reduced dt solve succeeded." << std::endl;
return;
}
}
// If we made it here, we still couldn't converge the solve after
// reducing deltat
libMesh::out << "DiffSolver::solve() did not succeed after "
<< reduce_deltat_on_diffsolver_failure
<< " attempts." << std::endl;
libmesh_convergence_failure();
} // end if (backtracking_failed || max_iterations)
} // end if (reduce_deltat_on_diffsolver_failure)
}
