Species Sensitivity Analysis for 1D Flames

interfaces/cython/cantera/onedim.py

@@ -169,6 +169,36 @@ def set_profile(self, component, positions, values):
         """
         super().set_profile(self.flame, component, positions, values)
 
+    def get_species_reaction_sensitivities(self, species: str, ix: int):
+        r"""
+        Compute the normalized sensitivities of a species
+        :math:`S_u` with respect to the reaction rate constants :math:`k_i`:
+
+        .. math::
+            s_i = \frac{k_i}{X} \frac{dX}{dk_i}
+        :param species:
+            Species of interest for sensitivity calculation (i.e "NO")
+        :param ix:
+            grid point index (0 is the first, -1 is the last point in the domain)
+        """
+
+        def g(sim):
+            return self.X[self.gas.species_index(species), ix]
+
+        Nvars = sum(D.n_components * D.n_points for D in self.domains)
+
+        # Index of X[ix] in the global solution vector
+        i_Su = self.inlet.n_components + self.flame.component_index(species) + self.domains[1].n_components * ix
+        dgdx = np.zeros(Nvars)
+        dgdx[i_Su] = 1
+
+        Su0 = g(self)
+
+        def perturb(sim, i, dp):
+            sim.gas.set_multiplier(1 + dp, i)
+
+        return self.solve_adjoint(perturb, self.gas.n_reactions, dgdx) / Su0
+
     @property
     def max_grid_points(self):
         """