Prescribed condition with particles

doc/modules/changes/20260711_lhy11009

@@ -0,0 +1,3 @@
+Changed: add support for updating the InitialComposition particle property using the prescribed solution plugin.
+<br>
+(Haoyuan Li, 2026/07/11)

include/aspect/particle/property/initial_composition.h

@@ -57,6 +57,13 @@ namespace aspect
           initialize_one_particle_property (const Point<dim> &position,
                                             std::vector<double> &particle_properties) const override;
 
+          /**
+          * @copydoc aspect::Particle::Property::Interface::update_particle_properties()
+          */
+          void
+          update_particle_properties (const ParticleUpdateInputs<dim> &inputs,
+                                      typename ParticleHandler<dim>::particle_iterator_range &particles) const override;
+
           /**
            * Returns an enum, which determines how this particle property is
            * initialized for particles that are created later than the initial

source/particle/property/initial_composition.cc

@@ -20,6 +20,7 @@
 
 #include <aspect/particle/property/initial_composition.h>
 #include <aspect/initial_composition/interface.h>
+#include <aspect/prescribed_solution/interface.h>
 
 namespace aspect
 {
@@ -80,6 +81,43 @@ namespace aspect
 
         return property_information;
       }
+
+      template <int dim>
+      void
+      InitialComposition<dim>::update_particle_properties(const ParticleUpdateInputs<dim> &/*inputs*/,
+                                                          typename ParticleHandler<dim>::particle_iterator_range &particles) const
+      {
+        const aspect::PrescribedSolution::Manager<dim> &prescribed_solution_manager = this->get_prescribed_solution();
+        const auto &plugin_objects = prescribed_solution_manager.get_active_plugins();
+
+
+        std::vector<Point<dim>> evaluation_points(1);
+        std::vector<unsigned int> component_indices(1);
+        std::vector<bool> component_is_constrained(1);
+        std::vector<double> constrained_component_value(1);
+
+        for (auto &particle : particles)
+          {
+            evaluation_points[0] = particle.get_location();
+
+            for (unsigned int j = 0; j < this->n_compositional_fields(); ++j)
+              {
+                component_indices[0] = this->introspection().component_indices.compositional_fields[j];
+                component_is_constrained[0] = false;
+                constrained_component_value[0] = 0.0;
+
+                for (const auto &plugin : plugin_objects)
+                  {
+                    typename DoFHandler<dim>::active_cell_iterator cell;
+                    plugin->constrain_solution(cell, evaluation_points, component_indices, component_is_constrained, constrained_component_value);
+                  }
+
+                if (component_is_constrained[0])
+                  particle.get_properties()[this->data_position+j] = constrained_component_value[0];
+              }
+          }
+      }
+
     }
   }
 }

tests/prescribed_solution_composition_initial_condition_particles.prm

@@ -0,0 +1,65 @@
+#########################################################
+# This is modified from the composition_passive.prm
+# parameter file by prescribing the compositional solution
+# from initial compositional fields and using the particle
+# method
+
+include $ASPECT_SOURCE_DIR/cookbooks/composition_passive/composition_passive.prm
+
+# Modify the original cookbook to end earlier
+set Start time                             = 0
+set End time                               = 0.1
+set Use years instead of seconds           = false
+
+# Modify the original cookbook to have coarser meshes
+subsection Mesh refinement
+  set Initial adaptive refinement        = 0
+  set Initial global refinement          = 3
+  set Time steps between mesh refinement = 0
+end
+
+# Modify the compositional fields to use particles
+subsection Compositional fields
+  set Number of fields = 2
+  set Compositional field methods = particles, particles
+  set Mapped particle properties = C_1: initial C_1, C_2: initial C_2
+end
+
+# Include the particles
+subsection Particles
+    set Minimum particles per cell = 25
+    set Maximum particles per cell = 100
+    set Load balancing strategy = remove and add particles
+    set List of particle properties = initial composition, position
+    set Interpolation scheme = bilinear least squares
+    set Update ghost particles = true
+    set Particle generator name = reference cell
+    subsection Generator
+        subsection Reference cell
+            set Number of particles per cell per direction = 7
+        end
+    end
+end
+
+# The next section prescribes the composition inside the domain
+# using a spatially varying function. An indicator function selects
+# the region where the composition is constrained.
+subsection Prescribed solution
+    set List of model names = initial composition
+    subsection Initial composition
+        subsection Indicator function
+            set Variable names = x, y
+            set Function expression = (x<1) ? 1:0
+        end
+    end
+end
+
+subsection Postprocess
+  set List of postprocessors = visualization
+
+  subsection Visualization
+    set Interpolate output = false
+    set Time between graphical output = 0.1
+    set Output format = gnuplot
+  end
+end

tests/prescribed_solution_composition_initial_condition_particles/screen-output

@@ -0,0 +1,31 @@
+
+Number of active cells: 64 (on 4 levels)
+Number of degrees of freedom: 1,526 (578+81+289+289+289)
+
+*** Timestep 0:  t=0 seconds, dt=0 seconds
+   Solving temperature system... 0 iterations.
+   Advecting particles...  done.
+   Solving Stokes system (GMG)... 11+0 iterations.
+
+   Postprocessing:
+     Writing graphical output: output-prescribed_solution_composition_initial_condition_particles/solution/solution-00000
+
+*** Timestep 1:  t=0.0625 seconds, dt=0.0625 seconds
+   Solving temperature system... 10 iterations.
+   Advecting particles...  done.
+   Solving Stokes system (GMG)... 7+0 iterations.
+
+   Postprocessing:
+
+*** Timestep 2:  t=0.1 seconds, dt=0.0375 seconds
+   Solving temperature system... 10 iterations.
+   Advecting particles...  done.
+   Solving Stokes system (GMG)... 12+0 iterations.
+
+   Postprocessing:
+     Writing graphical output: output-prescribed_solution_composition_initial_condition_particles/solution/solution-00001
+
+Termination requested by criterion: end time
+
+
+