MAINT: Minor changes related to diff-tpfa

src/porepy/models/constitutive_laws.py

@@ -2016,10 +2016,9 @@ def __mpfa_bound_pressure_discretization(
         # Otherwise, at the time of evaluation, internal_flux will be an AdArray, thus
         # we can access its val and jac attributes.
 
-        # EK: Testing on a case with no internal boundaries revealed a case where the
-        # external_bc was an AdArray. The precise reason for this is not clear (it could
-        # be a straightforward result of the rules of parsing), but to cover all cases,
-        # we do a if-else here.
+        # EK: Testing revealed a case where the external_bc was an AdArray. The precise
+        # reason for this is not clear (it could be a straightforward result of the
+        # rules of parsing), but to cover all cases, we do a if-else here.
         if isinstance(external_bc, pp.ad.AdArray):
             external_bc_val = external_bc.val
         else:

tests/numerics/fv/test_tpfa.py

@@ -749,13 +749,8 @@ def permeability(self, subdomains: list[pp.Grid]) -> pp.ad.Operator:
         all_vals[4::tensor_dim] = 1
         all_vals[8::tensor_dim] = 1
 
-        # Basis vector for the yy-component
-        e_yy = self.e_i(subdomains, i=4, dim=tensor_dim)
-
         return pp.wrap_as_dense_ad_array(
             all_vals, name="Constant_permeability_component"
-        ) + e_yy @ self.pressure(subdomains) * pp.ad.Scalar(
-            0  # Note the 0 here
         )