Use conductivity interface to remove code duplication

include/aspect/material_model/entropy_model.h

@@ -25,6 +25,7 @@
 
 #include <aspect/utilities.h>
 #include <aspect/simulator_access.h>
+#include <aspect/material_model/thermal_conductivity/interface.h>
 #include <aspect/material_model/rheology/ascii_depth_profile.h>
 #include <aspect/material_model/rheology/drucker_prager.h>
 #include <aspect/material_model/steinberger.h>
@@ -124,31 +125,11 @@ namespace aspect
         double max_lateral_eta_variation;
 
         /**
-         * The value for thermal conductivity. It can be a constant
-         * for the whole domain, or P-T dependent.
+         * The thermal conductivity parametrization to use. This material
+         * model supports either a constant thermal conductivity or a
+         * pressure- and temperature-dependent thermal conductivity.
          */
-        double thermal_conductivity_value;
-        double thermal_conductivity (const double temperature,
-                                     const double pressure,
-                                     const Point<dim> &position) const;
-
-        enum ConductivityFormulation
-        {
-          constant,
-          p_T_dependent
-        } conductivity_formulation;
-
-        /**
-         * Parameters for the temperature- and pressure dependence of the
-         * thermal conductivity.
-         */
-        std::vector<double> conductivity_transition_depths;
-        std::vector<double> reference_thermal_conductivities;
-        std::vector<double> conductivity_pressure_dependencies;
-        std::vector<double> conductivity_reference_temperatures;
-        std::vector<double> conductivity_exponents;
-        std::vector<double> saturation_scaling;
-        double maximum_conductivity;
+        std::unique_ptr<ThermalConductivity::Interface<dim>> thermal_conductivity;
 
         /**
          * Information about the location of data files.

include/aspect/material_model/steinberger.h

@@ -23,6 +23,7 @@
 
 #include <aspect/material_model/interface.h>
 #include <aspect/material_model/equation_of_state/thermodynamic_table_lookup.h>
+#include <aspect/material_model/thermal_conductivity/interface.h>
 
 #include <aspect/simulator_access.h>
 #include <deal.II/fe/component_mask.h>
@@ -116,7 +117,8 @@ namespace aspect
      * The viscosity of this model is based on the paper
      * Steinberger & Calderwood 2006: "Models of large-scale viscous flow in the
      * Earth's mantle with constraints from mineral physics and surface
-     * observations". The thermal conductivity is constant and the other
+     * observations". The thermal conductivity is constant or follows a
+     * pressure-temperature dependent approximation and the other
      * parameters are provided via lookup tables from the software PERPLEX.
      *
      * @ingroup MaterialModels
@@ -202,19 +204,6 @@ namespace aspect
 
 
       private:
-        /**
-         * Compute the pressure- and temperature-dependent thermal
-         * conductivity either as a constant value, or based on the
-         * equation given in Stackhouse et al., 2015: First-principles
-         * calculations of the lattice thermal conductivity of the
-         * lower mantle, or based on the equation given in Tosi et al.,
-         * 2013: Mantle dynamics with pressure- and temperature-dependent
-         * thermal expansivity and conductivity.
-         */
-        double thermal_conductivity (const double temperature,
-                                     const double pressure,
-                                     const Point<dim> &position) const;
-
         /**
          * Whether the compositional fields representing mass fractions
          * should be normalized to one when computing their fractions
@@ -248,31 +237,11 @@ namespace aspect
         bool use_lateral_average_temperature;
 
         /**
-         * The value of the thermal conductivity if a constant thermal
-         * conductivity is used for the whole domain.
-         */
-        double thermal_conductivity_value;
-
-        /**
-         * Enumeration for selecting which type of conductivity law to use.
-         */
-        enum ConductivityFormulation
-        {
-          constant,
-          p_T_dependent
-        } conductivity_formulation;
-
-        /**
-         * Parameters for the temperature- and pressure dependence of the
-         * thermal conductivity.
+         * The thermal conductivity parametrization to use. This material
+         * model supports either a constant thermal conductivity or a
+         * pressure- and temperature-dependent thermal conductivity.
          */
-        std::vector<double> conductivity_transition_depths;
-        std::vector<double> reference_thermal_conductivities;
-        std::vector<double> conductivity_pressure_dependencies;
-        std::vector<double> conductivity_reference_temperatures;
-        std::vector<double> conductivity_exponents;
-        std::vector<double> saturation_scaling;
-        double maximum_conductivity;
+        std::unique_ptr<ThermalConductivity::Interface<dim>> thermal_conductivity;
 
         /**
          * Compositional prefactors with which to multiply the reference viscosity.

include/aspect/material_model/thermal_conductivity/tosi_stackhouse.h

@@ -0,0 +1,114 @@
+/*
+  Copyright (C) 2025 - by the authors of the ASPECT code.
+
+  This file is part of ASPECT.
+
+  ASPECT is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2, or (at your option)
+  any later version.
+
+  ASPECT is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with ASPECT; see the file LICENSE.  If not see
+  <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef _aspect_material_model_thermal_conductivity_tosi_stackhouse_h
+#define _aspect_material_model_thermal_conductivity_tosi_stackhouse_h
+
+#include <aspect/material_model/thermal_conductivity/interface.h>
+
+
+namespace aspect
+{
+  namespace MaterialModel
+  {
+    namespace ThermalConductivity
+    {
+      using namespace dealii;
+
+      /**
+       * A class that implements a pressure- and temperature-dependent thermal conductivity
+       * following the formulation of
+       *
+       * Nicola Tosi, David A. Yuen, Nico de Koker, Renata M. Wentzcovitch,
+       * Mantle dynamics with pressure- and temperature-dependent thermal expansivity and conductivity,
+       * Physics of the Earth and Planetary Interiors, Volume 217,
+       * 2013, Pages 48-58, ISSN 0031-9201, https://doi.org/10.1016/j.pepi.2013.02.004,
+       *
+       * and
+       *
+       * Stephen Stackhouse, Lars Stixrude, Bijaya B. Karki,
+       * First-principles calculations of the lattice thermal conductivity of the lower mantle,
+       * Earth and Planetary Science Letters, Volume 427, 2015, Pages 11-17, ISSN 0012-821X,
+       * https://doi.org/10.1016/j.epsl.2015.06.050.
+       *
+       * The thermal conductivity parameter sets can be chosen in such a
+       * way that either the Stackhouse or the Tosi relations are used.
+       * The conductivity description can consist of several layers with
+       * different sets of parameters. Note that the Stackhouse
+       * parametrization is only valid for the lower mantle (bridgmanite).
+       *
+       * The default parameters of this class use the Tosi parametrization in the upper
+       * mantle and the Stackhouse parametrization in the lower mantle, which is how
+       * it was used in the publication
+       *
+       * Juliane Dannberg, Rene Gassmöller, Daniele Thallner, Frederick LaCombe, Courtney Sprain,
+       * Changes in core–mantle boundary heat flux patterns throughout the supercontinent cycle,
+       * Geophysical Journal International, Volume 237, Issue 3, June 2024, Pages 1251–1274, https://doi.org/10.1093/gji/ggae075,
+       *
+       * which introduced this implementation.
+       *
+       * @ingroup MaterialModels
+       */
+      template <int dim>
+      class TosiStackhouse : public Interface<dim>, public aspect::SimulatorAccess<dim>
+      {
+        public:
+          /**
+           * Function to compute the thermal conductivities in @p out given the
+           * inputs in @p in.
+           */
+          void evaluate (const MaterialModel::MaterialModelInputs<dim> &in,
+                         MaterialModel::MaterialModelOutputs<dim> &out) const override;
+
+          /**
+           * Declare the parameters this plugin takes through input files.
+           */
+          static
+          void
+          declare_parameters (ParameterHandler &prm);
+
+          /**
+           * Read the parameters from the parameter file.
+           */
+          void
+          parse_parameters (ParameterHandler &prm) override;
+
+        private:
+          /**
+           * Parameters for the temperature and pressure dependence of the
+           * thermal conductivity.
+           */
+          std::vector<double> conductivity_transition_depths;
+          std::vector<double> reference_thermal_conductivities;
+          std::vector<double> conductivity_pressure_dependencies;
+          std::vector<double> conductivity_reference_temperatures;
+          std::vector<double> conductivity_exponents;
+          std::vector<double> saturation_scaling;
+
+          /**
+           * The maximum allowed thermal conductivity.
+           */
+          double maximum_conductivity;
+      };
+    }
+  }
+}
+
+#endif