pybamm-team#1349 Rob's suggestion

pybamm/models/submodels/electrolyte_conductivity/base_electrolyte_conductivity.py

@@ -274,7 +274,6 @@ def _get_whole_cell_variables(self, variables):
             The variables including the whole-cell electrolyte potentials
             and currents.
         """
-        param = self.param
 
         phi_e_n = variables["Negative electrolyte potential"]
         phi_e_s = variables["Separator electrolyte potential"]
@@ -285,6 +284,36 @@ def _get_whole_cell_variables(self, variables):
         i_e_p = variables["Positive electrolyte current density"]
         i_e = pybamm.Concatenation(i_e_n, i_e_s, i_e_p)
 
+        variables.update(
+            self._get_standard_potential_variables(phi_e_n, phi_e_s, phi_e_p)
+        )
+        variables.update(self._get_standard_current_variables(i_e))
+
+        return variables
+
+    def _get_electrolyte_overpotentials(self, variables):
+        """
+        A private function to obtain the electrolyte overpotential and Ohmic losses.
+        Note: requires 'variables' to contain the potential, electrolyte concentration
+        and temperature the subdomains: 'negative electrode', 'separator', and
+        'positive electrode'.
+
+        Parameters
+        ----------
+        variables : dict
+            The variables that have been set in the rest of the model.
+
+        Returns
+        -------
+        variables : dict
+            The variables including the whole-cell electrolyte potentials
+            and currents.
+        """
+        param = self.param
+
+        phi_e_n = variables["Negative electrolyte potential"]
+        phi_e_p = variables["Positive electrolyte potential"]
+
         c_e_n = variables["Negative electrolyte concentration"]
         c_e_s = variables["Separator electrolyte concentration"]
         c_e_p = variables["Positive electrolyte concentration"]
@@ -326,10 +355,6 @@ def _get_whole_cell_variables(self, variables):
             pybamm.x_average(phi_e_p) - pybamm.x_average(phi_e_n) - eta_c_av
         )
 
-        variables.update(
-            self._get_standard_potential_variables(phi_e_n, phi_e_s, phi_e_p)
-        )
-        variables.update(self._get_standard_current_variables(i_e))
         variables.update(self._get_split_overpotential(eta_c_av, delta_phi_e_av))
 
         return variables

pybamm/models/submodels/electrolyte_conductivity/full_conductivity.py

@@ -39,50 +39,13 @@ def get_coupled_variables(self, variables):
         c_e = variables["Electrolyte concentration"]
         phi_e = variables["Electrolyte potential"]
 
-        c_e_n, c_e_s, c_e_p = c_e.orphans
-        phi_e_n, _, phi_e_p = phi_e.orphans
-        T_n, T_s, T_p = T.orphans
-
         i_e = (param.kappa_e(c_e, T) * tor * param.gamma_e / param.C_e) * (
             param.chi(c_e, T) * (1 + param.Theta * T) * pybamm.grad(c_e) / c_e
             - pybamm.grad(phi_e)
         )
 
-        # concentration overpotential
-        indef_integral_n = pybamm.IndefiniteIntegral(
-            param.chi(c_e_n, T_n)
-            * (1 + param.Theta * T_n)
-            * pybamm.grad(c_e_n)
-            / c_e_n,
-            pybamm.standard_spatial_vars.x_n,
-        )
-        indef_integral_s = pybamm.IndefiniteIntegral(
-            param.chi(c_e_s, T_s)
-            * (1 + param.Theta * T_s)
-            * pybamm.grad(c_e_s)
-            / c_e_s,
-            pybamm.standard_spatial_vars.x_s,
-        )
-        indef_integral_p = pybamm.IndefiniteIntegral(
-            param.chi(c_e_p, T_p)
-            * (1 + param.Theta * T_p)
-            * pybamm.grad(c_e_p)
-            / c_e_p,
-            pybamm.standard_spatial_vars.x_p,
-        )
-
-        integral_n = indef_integral_n
-        integral_s = indef_integral_s + pybamm.boundary_value(integral_n, "right")
-        integral_p = indef_integral_p + pybamm.boundary_value(integral_s, "right")
-
-        eta_c_av = pybamm.x_average(integral_p) - pybamm.x_average(integral_n)
-
-        delta_phi_e_av = (
-            pybamm.x_average(phi_e_p) - pybamm.x_average(phi_e_n) - eta_c_av
-        )
-
         variables.update(self._get_standard_current_variables(i_e))
-        variables.update(self._get_split_overpotential(eta_c_av, delta_phi_e_av))
+        variables.update(self._get_electrolyte_overpotentials(variables))
 
         return variables
 

pybamm/models/submodels/electrolyte_conductivity/surface_potential_form/full_surface_form_conductivity.py

@@ -95,6 +95,7 @@ def get_coupled_variables(self, variables):
 
         if self.domain == "Positive":
             variables.update(self._get_whole_cell_variables(variables))
+            variables.update(self._get_electrolyte_overpotentials(variables))
 
         return variables
 

tests/unit/test_models/test_submodels/test_electrolyte_conductivity/test_full_conductivity.py

@@ -19,6 +19,12 @@ def test_public_functions(self):
         variables = {
             "Electrolyte tortuosity": a,
             "Electrolyte concentration": pybamm.Concatenation(a_n, a_s, a_p),
+            "Negative electrolyte concentration": a_n,
+            "Separator electrolyte concentration": a_s,
+            "Positive electrolyte concentration": a_p,
+            "Negative electrode temperature": a_n,
+            "Separator temperature": a_s,
+            "Positive electrode temperature": a_p,
             "Negative "
             + surf: pybamm.FullBroadcast(a, "negative electrode", "current collector"),
             "Positive "