Initial conditions in mixed-domain cases

src/festim/hydrogen_transport_problem.py

@@ -40,6 +40,7 @@
     as_fenics_constant,
     get_interpolation_points,
     is_it_time_to_export,
+    nmm_interpolate,
 )
 from festim.material import SolubilityLaw
 
@@ -1251,20 +1252,27 @@ def create_initial_conditions(self):
         the previous solution of the condition's species"""
 
         for condition in self.initial_conditions:
-            V = condition.species.subdomain_to_function_space[condition.volume]
+            idx = self.species.index(condition.species)
 
-            condition.create_expr_fenics(
-                mesh=self.mesh.mesh,
-                temperature=self.temperature_fenics,
-                function_space=V,
-            )
+            # if the value given is a function, then directly interpolate it on the
+            # previous solution of the species
+            if isinstance(condition.value, fem.Function):
+                nmm_interpolate(condition.volume.u_n.sub(idx), condition.value)
 
-            # assign to previous solution of species
-            entities = self.volume_meshtags.find(condition.volume.id)
-            idx = self.species.index(condition.species)
-            condition.volume.u_n.sub(idx).interpolate(
-                condition.expr_fenics, cells1=entities
-            )
+            else:
+                V = condition.species.subdomain_to_function_space[condition.volume]
+
+                condition.create_expr_fenics(
+                    mesh=self.mesh.mesh,
+                    temperature=self.temperature_fenics,
+                    function_space=V,
+                )
+
+                # assign to previous solution of species
+                entities = self.volume_meshtags.find(condition.volume.id)
+                condition.volume.u_n.sub(idx).interpolate(
+                    condition.expr_fenics, cells1=entities
+                )
 
     def define_function_spaces(
         self, subdomain: _subdomain.VolumeSubdomain, element_degree=1
@@ -1735,9 +1743,9 @@ def initialise_exports(self):
                         engine="BP5",
                     )
                 else:
-                    raise NotImplementedError(
-                        f"Export type {type(export)} not implemented for "
-                        f"mixed-domain approach"
+                    adios4dolfinx.write_mesh(
+                        export.filename,
+                        mesh=functions[0].function_space.mesh,
                     )
 
         # compute diffusivity function for surface fluxes
@@ -1787,11 +1795,20 @@ def post_processing(self):
                     )
                 if isinstance(export, exports.VTXSpeciesExport):
                     if export._checkpoint:
-                        raise NotImplementedError(
-                            f"Export type {type(export)} not implemented "
-                            f"for mixed-domain approach"
-                        )
-                export.writer.write(float(self.t))
+                        for species in export.field:
+                            post_processing_solution = (
+                                species.subdomain_to_post_processing_solution[
+                                    export._subdomain
+                                ]
+                            )
+                            adios4dolfinx.write_function(
+                                export.filename,
+                                post_processing_solution,
+                                time=float(self.t),
+                                name=species.name,
+                            )
+                    else:
+                        export.writer.write(float(self.t))
 
             # handle derived quantities
             if isinstance(export, exports.SurfaceQuantity):

test/test_initial_condition.py

@@ -434,3 +434,104 @@ def test_initial_condition_continuous_multimaterial():
     # assert value of spe1 is not all the same across the domain
 
     assert not np.allclose(my_model.u_n.x.array[:], intial_cond_value)
+
+
+def test_initial_condition_mixed_domain():
+    """Test the initial condition in a multi-material discontinous case"""
+
+    my_model = F.HydrogenTransportProblemDiscontinuous()
+
+    vertices_left = np.linspace(0, 0.5, 500)
+    vertices_right = np.linspace(0.5, 1, 500)
+    vertices = np.concatenate((vertices_left, vertices_right))
+    my_model.mesh = F.Mesh1D(vertices)
+
+    # assumes the same diffusivity for all species
+    material_left = F.Material(D_0=1e-01, E_D=0, K_S_0=1, E_K_S=0)
+    material_right = F.Material(D_0=1e-01, E_D=0, K_S_0=2, E_K_S=0)
+
+    vol1 = F.VolumeSubdomain1D(id=1, borders=[0, 0.5], material=material_left)
+    vol2 = F.VolumeSubdomain1D(id=2, borders=[0.5, 1], material=material_right)
+    my_model.subdomains = [vol1, vol2]
+
+    spe1 = F.Species("1", mobile=True, subdomains=[vol1, vol2])
+    my_model.species = [spe1]
+
+    my_model.temperature = 300
+
+    intial_cond_value = 100
+    V = fem.functionspace(my_model.mesh.mesh, ("CG", 1))
+    u = fem.Function(V)
+    u.x.array[:] = intial_cond_value
+
+    my_model.initial_conditions = [
+        F.InitialConcentration(value=u, species=spe1, volume=vol1),
+    ]
+
+    dt = F.Stepsize(0.1)
+    my_model.settings = F.Settings(
+        atol=1e-10, rtol=1e-10, final_time=5, transient=True, stepsize=dt
+    )
+
+    my_model.initialise()
+
+    # assert value of spe1 in vol1
+    left_spe1_un = vol1.u.sub(0)
+
+    assert not np.allclose(left_spe1_un.x.array[:], intial_cond_value)
+
+
+def test_initial_condition_mixed_domain_multispecies():
+    """Test the initial condition in a multispecies multi-material discontinous case"""
+
+    my_model = F.HydrogenTransportProblemDiscontinuous()
+
+    vertices_left = np.linspace(0, 0.5, 500)
+    vertices_right = np.linspace(0.5, 1, 500)
+    vertices = np.concatenate((vertices_left, vertices_right))
+    my_model.mesh = F.Mesh1D(vertices)
+
+    # assumes the same diffusivity for all species
+    material_left = F.Material(D_0=1e-01, E_D=0, K_S_0=1, E_K_S=0)
+    material_right = F.Material(D_0=1e-01, E_D=0, K_S_0=2, E_K_S=0)
+
+    vol1 = F.VolumeSubdomain1D(id=1, borders=[0, 0.5], material=material_left)
+    vol2 = F.VolumeSubdomain1D(id=2, borders=[0.5, 1], material=material_right)
+    my_model.subdomains = [vol1, vol2]
+
+    spe1 = F.Species("1", mobile=True, subdomains=[vol1, vol2])
+    spe2 = F.Species("2", mobile=True, subdomains=[vol1, vol2])
+    my_model.species = [spe1, spe2]
+
+    my_model.temperature = 300
+
+    intial_cond_value_1 = 100
+    intial_cond_value_2 = 200
+    V = fem.functionspace(my_model.mesh.mesh, ("CG", 1))
+    u = fem.Function(V)
+    u.x.array[:] = intial_cond_value_1
+
+    V2 = fem.functionspace(my_model.mesh.mesh, ("CG", 1))
+    u2 = fem.Function(V2)
+    u2.x.array[:] = intial_cond_value_2
+
+    my_model.initial_conditions = [
+        F.InitialConcentration(value=u, species=spe1, volume=vol1),
+        F.InitialConcentration(value=u2, species=spe2, volume=vol1),
+    ]
+
+    dt = F.Stepsize(0.1)
+    my_model.settings = F.Settings(
+        atol=1e-10, rtol=1e-10, final_time=5, transient=True, stepsize=dt
+    )
+
+    my_model.initialise()
+
+    spe1_left, spe1_to_vol1 = vol1.u_n.function_space.sub(0).collapse()
+    spe2_left, spe2_to_vol1 = vol1.u_n.function_space.sub(1).collapse()
+
+    prev_solution_spe1_left = vol1.u_n.x.array[spe1_to_vol1]
+    prev_solution_spe2_left = vol1.u_n.x.array[spe2_to_vol1]
+
+    assert np.allclose(prev_solution_spe1_left, intial_cond_value_1)
+    assert np.allclose(prev_solution_spe2_left, intial_cond_value_2)