Adding user-defined picard convergence postprocessor in PicardSolve i…

…daholab#14642

framework/include/executioners/PicardSolve.h

@@ -113,6 +113,12 @@ class PicardSolve : public SolveObject
   Real _picard_rel_tol;
   /// Absolute tolerance on residual norm
   Real _picard_abs_tol;
+  /// Postprocessor value for user-defined picard convergence check
+  const PostprocessorValue * _picard_custom_pp;
+  /// Relative tolerance on postprocessor value
+  Real _custom_rel_tol;
+  /// Absolute tolerance on postprocessor value
+  Real _custom_abs_tol;
   /// Whether or not we force evaluation of residual norms even without multiapps
   bool _picard_force_norms;
   /// Relaxation factor for Picard Iteration

framework/src/executioners/PicardSolve.C

@@ -51,6 +51,26 @@ PicardSolve::validParams()
                         "during Picard iterations.  This check is "
                         "performed based on the Master app's nonlinear "
                         "residual.");
+  params.addParam<PostprocessorName>("picard_custom_pp",
+                                     "Postprocessor for custom picard convergence check.");
+  params.addParam<Real>("custom_rel_tol",
+                        1e-8,
+                        "The relative nonlinear residual drop to shoot for "
+                        "during Picard iterations.  This check is "
+                        "performed based on postprocessor defined by "
+                        "picard_custom_pp residual.");
+  params.addParam<Real>("custom_abs_tol",
+                        1e-50,
+                        "The absolute nonlinear residual to shoot for "
+                        "during Picard iterations.  This check is "
+                        "performed based on postprocessor defined by "
+                        "picard_custom_pp residual.");
+  params.addParam<bool>("direct_pp_value",
+                        false,
+                        "True to use direct postprocessor value "
+                        "(scaled by value on first iteration). "
+                        "False (default) to use difference in postprocessor "
+                        "value between picard iterations.");
   params.addParam<bool>(
       "picard_force_norms",
       false,
@@ -68,7 +88,7 @@ PicardSolve::validParams()
 
   params.addParamNamesToGroup("picard_max_its accept_on_max_picard_iteration "
                               "disable_picard_residual_norm_check picard_rel_tol "
-                              "picard_abs_tol picard_force_norms "
+                              "picard_abs_tol picard_custom_pp picard_force_norms "
                               "relaxation_factor relaxed_variables",
                               "Picard");
 
@@ -91,6 +111,12 @@ PicardSolve::PicardSolve(Executioner * ex)
     _has_picard_norm(!getParam<bool>("disable_picard_residual_norm_check")),
     _picard_rel_tol(getParam<Real>("picard_rel_tol")),
     _picard_abs_tol(getParam<Real>("picard_abs_tol")),
+    _picard_custom_pp(
+        isParamValid("picard_custom_pp")
+            ? &_problem.getPostprocessorValue(getParam<PostprocessorName>("picard_custom_pp"))
+            : nullptr),
+    _custom_rel_tol(getParam<Real>("custom_rel_tol")),
+    _custom_abs_tol(getParam<Real>("custom_abs_tol")),
     _picard_force_norms(getParam<bool>("picard_force_norms")),
     _relax_factor(getParam<Real>("relaxation_factor")),
     _relaxed_vars(getParam<std::vector<std::string>>("relaxed_variables")),
@@ -163,6 +189,8 @@ PicardSolve::solve()
     }
   }
 
+  Real pp_scaling = 1.0;
+
   for (_picard_it = 0; _picard_it < _picard_max_its; ++_picard_it)
   {
     if (_has_picard_its)
@@ -192,6 +220,11 @@ PicardSolve::solve()
                << '\n';
     }
 
+    // Save last postprocessor value as value before solve
+    Real pp_old = 0.0;
+    if (_picard_custom_pp && _picard_it > 0 && !getParam<bool>("direct_pp_value"))
+      pp_old = *_picard_custom_pp;
+
     Real begin_norm_old = (_picard_it > 0 ? _picard_timestep_begin_norm[_picard_it - 1]
                                           : std::numeric_limits<Real>::max());
     Real end_norm_old = (_picard_it > 0 ? _picard_timestep_end_norm[_picard_it - 1]
@@ -203,6 +236,15 @@ PicardSolve::solve()
                                      _picard_timestep_end_norm[_picard_it],
                                      relax,
                                      relaxed_dofs);
+    // Calculate error from postprocessor values
+    Real pp_new = std::numeric_limits<Real>::max();
+    if (_picard_custom_pp)
+    {
+      if ((_picard_it == 0 && getParam<bool>("direct_pp_value")) ||
+          !getParam<bool>("direct_pp_value"))
+        pp_scaling = *_picard_custom_pp;
+      pp_new = *_picard_custom_pp;
+    }
 
     if (solve_converged)
     {
@@ -243,6 +285,16 @@ PicardSolve::solve()
           _picard_status = MoosePicardConvergenceReason::CONVERGED_CUSTOM;
           break;
         }
+        if (std::abs(pp_new - pp_old) < _custom_abs_tol)
+        {
+          _picard_status = MoosePicardConvergenceReason::CONVERGED_CUSTOM;
+          break;
+        }
+        if (std::abs((pp_new - pp_old) / pp_scaling) < _custom_rel_tol)
+        {
+          _picard_status = MoosePicardConvergenceReason::CONVERGED_CUSTOM;
+          break;
+        }
         if (_picard_it + 1 == _picard_max_its)
         {
           if (_accept_max_it)

test/tests/multiapps/picard/picard_custom_postprocessor.i

@@ -0,0 +1,108 @@
+[Mesh]
+  type = GeneratedMesh
+  dim = 2
+  nx = 10
+  ny = 10
+  parallel_type = replicated
+[]
+
+[Variables]
+  [./u]
+  [../]
+[]
+
+[AuxVariables]
+  [./v]
+  [../]
+[]
+
+[Kernels]
+  [./diff]
+    type = CoefDiffusion
+    variable = u
+    coef = 0.1
+  [../]
+  [./force_u]
+    type = CoupledForce
+    variable = u
+    v = v
+  [../]
+[]
+
+[BCs]
+  [./left]
+    type = DirichletBC
+    variable = u
+    boundary = left
+    value = 0
+  [../]
+  [./right]
+    type = DirichletBC
+    variable = u
+    boundary = right
+    value = 1
+  [../]
+[]
+
+[Postprocessors]
+  [./unorm_begin]
+    type = ElementL2Norm
+    variable = u
+    execute_on = 'initial timestep_begin'
+    outputs = none
+  [../]
+  [./unorm]
+    type = ElementL2Norm
+    variable = u
+    execute_on = 'initial timestep_end'
+  [../]
+  [./unorm_err]
+    type = RelativeDifferencePostprocessor
+    value1 = unorm
+    value2 = unorm_begin
+    outputs = none
+  [../]
+  [./vnorm]
+    type = ElementL2Norm
+    variable = v
+    execute_on = 'initial timestep_end'
+  [../]
+[]
+
+[Executioner]
+  type = Steady
+  petsc_options_iname = '-pc_type -pc_hypre_type'
+  petsc_options_value = 'hypre boomeramg'
+  picard_max_its = 30
+  disable_picard_residual_norm_check = true
+  picard_custom_pp = unorm_err
+[]
+
+[Outputs]
+  exodus = true
+[]
+
+[MultiApps]
+  [./sub]
+    type = FullSolveMultiApp
+    input_files = steady_picard_sub.i
+    no_backup_and_restore = true
+  [../]
+[]
+
+[Transfers]
+  [./v_from_sub]
+    type = MultiAppNearestNodeTransfer
+    direction = from_multiapp
+    multi_app = sub
+    source_variable = v
+    variable = v
+  [../]
+  [./u_to_sub]
+    type = MultiAppNearestNodeTransfer
+    direction = to_multiapp
+    multi_app = sub
+    source_variable = u
+    variable = u
+  [../]
+[]

test/tests/multiapps/picard/tests

@@ -96,4 +96,25 @@
     issues = '#9038'
     requirement = "The system shall allow steady-state Picard iteration with pseudo-transient multiapps"
   [../]
+
+  [./steady_with_postprocessor_convergence]
+    type = 'Exodiff'
+    input = 'picard_custom_postprocessor.i'
+    exodiff = 'picard_custom_postprocessor_out.e picard_custom_postprocessor_out_sub0.e'
+    cli_args = 'Executioner/direct_pp_value=true Executioner/custom_abs_tol=1e-4'
+    recover = false
+    design = 'multiapps/FullSolveMultiApp.md'
+    issues = '#14642'
+    requirement = "The system shall allow convergence check with user defined postprocessor directly."
+  [../]
+  [./steady_with_postprocessor_diff_convergence]
+    type = 'Exodiff'
+    input = 'picard_custom_postprocessor.i'
+    exodiff = 'picard_custom_diff_out.e picard_custom_diff_out_sub0.e'
+    cli_args = 'Executioner/picard_custom_pp=unorm Executioner/custom_rel_tol=1e-4 Outputs/file_base=picard_custom_diff_out'
+    recover = false
+    design = 'multiapps/FullSolveMultiApp.md'
+    issues = '#14642'
+    requirement = "The system shall allow convergence check with the convergence of a user defined postprocessor."
+  [../]
 []