BCs were not updated when only T was changing

src/festim/boundary_conditions/dirichlet_bc.py

@@ -127,14 +127,16 @@ def update(self, t: float):
         """Updates the boundary condition value
 
         Args:
-            t (float): the time
+            t: the time
         """
         if callable(self.value):
             arguments = self.value.__code__.co_varnames
             if isinstance(self.value_fenics, fem.Constant) and "t" in arguments:
                 self.value_fenics.value = self.value(t=t)
             else:
                 self.value_fenics.interpolate(self.bc_expr)
+        elif self.bc_expr is not None:
+            self.value_fenics.interpolate(self.bc_expr)
 
 
 class FixedConcentrationBC(DirichletBCBase):

src/festim/problem_change_of_var.py

@@ -187,7 +187,9 @@ def create_dirichletbc_form(self, bc: festim.FixedConcentrationBC):
             function_space_value = bc.species.collapsed_function_space
 
         # create K_S function
-        Q0 = fem.functionspace(self.mesh.mesh, ("DG", 0))
+        Q0 = fem.functionspace(
+            self.mesh.mesh, ("DG", 0)
+        )  # NOTE K_S0 and E_KS could be constants here and don't have to be defined on several materials
         K_S0 = fem.Function(Q0)
         E_KS = fem.Function(Q0)
         for subdomain in self.volume_subdomains:
@@ -233,3 +235,11 @@ def create_dirichletbc_form(self, bc: festim.FixedConcentrationBC):
         )
 
         return form
+
+    def update_time_dependent_values(self):
+        super().update_time_dependent_values()
+
+        if self.temperature_time_dependent:
+            for bc in self.boundary_conditions:
+                if isinstance(bc, boundary_conditions.FixedConcentrationBC):
+                    bc.update(self.t)