Plasma treatment enhancements

AUTHORS.md

@@ -16,6 +16,7 @@ update, please report on Cantera's
 - **Philip Berndt**
 - **Guus Bertens** [@guusbertens](https://github.com/guusbertens) - Eindhoven University of Technology
 - **Wolfgang Bessler** [@wbessler](https://github.com/wbessler) - Offenburg University of Applied Science
+- **Gaétan Bizot** [@Gaetanosaure] (https://github.com/Gaetanosaure) - University of Florence
 - **Paul Blum** [@paulblum](https://github.com/paulblum)
 - **Tilman Bremer**
 - **Victor Brunini** [@vbrunini](https://github.com/vbrunini) - Sandia National Laboratory

include/cantera/kinetics/ElectronCollisionPlasmaRate.h

@@ -211,6 +211,18 @@ class ElectronCollisionPlasmaRate : public ReactionRate
     //! Update the value of #m_crossSectionsInterpolated [m2]
     void updateInterpolatedCrossSection(span<const double>);
 
+    //! Returns the name of the collision linking the reaction to the data stored in electron-collision
+    const string& collisionName() const;
+
+    //! Return whether this rate object has tabulated cross-section data.
+    bool hasCrossSectionData() const;
+
+    //! Enters the collision data found in the YAML when it is given in the old (still accepted but deprecated) format.
+    void applyCollisionData(const AnyMap& node);
+
+    //! Checks the validity of the YAML entry.
+    void validateCollisionData(const AnyMap& node) const;
+
 private:
     //! The name of the kind of electron collision
     string m_kind;
@@ -222,7 +234,7 @@ class ElectronCollisionPlasmaRate : public ReactionRate
     string m_product;
 
     //! The energy threshold of electron collision
-    double m_threshold;
+    double m_threshold = 0;
 
     //! electron energy levels [eV]
     vector<double> m_energyLevels;
@@ -240,11 +252,19 @@ class ElectronCollisionPlasmaRate : public ReactionRate
     //! collision cross sections [m2] after interpolation
     vector<double> m_crossSectionsInterpolated;
 
-    //! collision cross section [m2] interpolated on #m_energyLevels offset by the
-    //! threshold energy (the first energy level).
-    //! This is used for the calculation of the super-elastic collision reaction
-    //! rate coefficient.
+    //! Super-elastic cross sections [m²] interpolated on the shared EEDF grid
+    //! after shifting the tabulated energy levels by #m_threshold.
     Eigen::ArrayXd m_crossSectionsOffset;
+
+    //! The name of the collision field in the new YAML PlasmaPhase implementation
+    string m_collisionName;
+
+    //! Check whether a YAML node entry offers some cross section data
+    bool m_hasCrossSectionData = false;
+
+    //! Get the energy threshold for the reaction from the energy levels and cross sections data if threshold is not given in the reaction
+    void setDefaultThreshold();
+
 };
 
 }

include/cantera/kinetics/TwoTempPlasmaRate.h

@@ -48,12 +48,14 @@ struct TwoTempPlasmaData : public ReactionData
  * activation energy for electron is included.
  *
  *   @f[
- *        k_f =  A T_e^b \exp (-E_{a,g}/RT) \exp (E_{a,e} (T_e - T)/(R T T_e))
+ *        k_f = A T^{b_g} T_e^b * exp(-E_{a,g}/RT) * exp(E_{a,e}(T_e - T)/(R T T_e))
  *   @f]
  *
  * where @f$ T_e @f$ is the electron temperature, @f$ E_{a,g} @f$ is the activation
  * energy for gas, and @f$ E_{a,e} @f$ is the activation energy for electron, see
  * Kossyi, et al. @cite kossyi1992.
+ * The optional gas temperature exponent b_g defaults to zero, which stricly corresponds to @cite kossyi1992. 
+ * If b_g is non-zero, a generalisation is used.
  *
  * @ingroup arrheniusGroup
  */
@@ -66,10 +68,13 @@ class TwoTempPlasmaRate : public ArrheniusBase
     /*!
      *  @param A  Pre-exponential factor. The unit system is (kmol, m, s); actual units
      *      depend on the reaction order and the dimensionality (surface or bulk).
-     *  @param b  Temperature exponent (non-dimensional)
+     *  @param b   Electron temperature exponent (non-dimensional)
      *  @param Ea  Activation energy in energy units [J/kmol]
      *  @param EE  Activation electron energy in energy units [J/kmol]
+     *  @param bg  Gas temperature exponent (non-dimensional). If not specified, defaults to 0.
      */
+    TwoTempPlasmaRate(double A, double b, double Ea, double EE, double bg);
+
     TwoTempPlasmaRate(double A, double b, double Ea=0.0, double EE=0.0);
 
     TwoTempPlasmaRate(const AnyMap& node, const UnitStack& rate_units={});
@@ -90,12 +95,12 @@ class TwoTempPlasmaRate : public ArrheniusBase
      */
     double evalFromStruct(const TwoTempPlasmaData& shared_data) const {
         // m_E4_R is the electron activation (in temperature units)
-        return m_A * std::exp(m_b * shared_data.logTe -
-                              m_Ea_R * shared_data.recipT +
-                              m_E4_R * (shared_data.electronTemp - shared_data.temperature)
-                              * shared_data.recipTe * shared_data.recipT);
+            return m_A * std::exp(m_bg * shared_data.logT + m_b * shared_data.logTe
+                    - m_Ea_R * shared_data.recipT + m_E4_R * (shared_data.electronTemp - shared_data.temperature)
+                    * shared_data.recipTe * shared_data.recipT);
     }
 
+
     //! Evaluate derivative of reaction rate with respect to temperature
     //! divided by reaction rate
     /*!
@@ -109,6 +114,9 @@ class TwoTempPlasmaRate : public ArrheniusBase
     double activationElectronEnergy() const {
         return m_E4_R * GasConstant;
     }
+
+protected:
+    double m_bg = 0.0; //!< Gas temperature exponent
 };
 
 }