### 3.2.10. CFX-Solver Output File (Combustion Runs)

Running a combustion simulation in the CFX-Solver is similar to multicomponent fluid runs with the extensions explained in the following.

#### 3.2.10.1. Multicomponent Specific Enthalpy Diffusion (MCF)

This applies also to non-reacting multicomponent flow. For multicomponent fluids with heat transfer, the diffusion term assembly modes are reported for the molecular and the turbulent diffusion, respectively. The option for each part may be either generic assembly or unity Lewis number assumption,

    +--------------------------------------------------------------------+
    |            Multi-Component Specific Enthalpy Diffusion             |
    +--------------------------------------------------------------------+

    Enthalpy equation assembly for secondary terms derived from multi-
    component species transport.  Molecular and turbulent transport may
    use either Unity Lewis Number (Le=1) assumption or generic assembly.

    Domain Name : Default Domain
        Mixture                                   (Le_mol=gen, Le_trb=1  )

#### 3.2.10.2. Single Step Reactions Heat Release

For single step reactions the heat release per chemical amount of reaction is reported. Numbers are in solver units. Positive numbers indicate exothermic reactions (heat is released) and negative numbers indicate endothermic reactions (energy required for the reaction to occur). The total heat release in the domain resulting from a particular reaction can be computed by multiplying the reactions heat release by its molar reaction rate and integrating over the domain.

    +--------------------------------------------------------------------+
    |                 Single Step Reactions Heat Release                 |
    +--------------------------------------------------------------------+
    Enthalpy per [mol] of reaction at reference conditions
    (Pressure= 1.01325E+05, Temperature= 2.98150E+02)
        HCO Oxygen                                           =  5.5799E+05
        HCN NO Destruction PDF                               =  1.8194E+05
        HCN NO Formation PDF                                 =  1.3458E+03
        Reburn NO Fuel Gas PDF                               =  2.7885E+05
        Prompt NO Fuel Gas PDF                               = -9.0298E+04
        Thermal NO PDF                                       = -1.8060E+05
        Fuel Gas Oxygen                                      =  5.1127E+05

#### 3.2.10.3. Stoichiometric Mixture Fraction

The stoichiometric mixture fraction is reported when a `Flamelet` model or `Burning Velocity` model is used. If the stoichiometric mixture fraction is not specified in the definition of the `Flamelet` library reaction object, the stoichiometric value is reported as `<unknown>`.

    +--------------------------------------------------------------------+
    |                  Stoichiometric Mixture Fraction                   |
    +--------------------------------------------------------------------+
    Stoichiometric mixture fraction (Zst) for fluids with mixture
    fraction combustion models.
    Domain Name : run
        Mixture                                           Zst = 5.5000E-02

#### 3.2.10.4. Hydrocarbon Fuel Model: Proximate / Ultimate Analysis

For the hydrocarbon fuel model (the `Hydrocarbon Fuel` option for the Material setting) the results of the proximate/ultimate analysis calculation are reported:

- The initial composition of the particles (component mass fractions). These values will be applied when no user-specified initial particle composition is specified (default).

- Molar mass and reference specific enthalpy for the `Volatiles` material that is released to the gas phase. The values reported here by default overrule the data specified in the corresponding material object.

- For single step reactions the relative stoichiometric coefficients, which are derived from the fuel analysis, are reported. These values are applied when the `Fuel Analysis` option is specified in the reaction for the corresponding reactant or product.

- For multiphase reactions the relative mass coefficients, which are derived from the fuel analysis, are reported. These values are applied when the `Fuel Analysis` option is specified in the reaction for the corresponding reactant or product.

      ======================================================================
                        HC Fuel Proximate/Ultimate Analysis
      ======================================================================
      Initial mass fractions for particle : HC Fuel
          Ash                                                  =  1.2580E-01
          Char                                                 =  0.0000E+00
          Raw Combustible                                      =  8.7420E-01
      Volatiles material properties : Fuel Gas
          Molar Mass [kg/kmol]                                 =      18.234
          Ref. Spec. Enthalpy (p= 1.01325E+05, T= 2.98150E+02) = -7.1827E+06
      +--------------------------------------------------------------------+
      |              Autocomputed Stoichiometric Coefficients              |
      +--------------------------------------------------------------------+
      Reaction (volatiles oxidation) : Fuel Gas Oxygen
        Reactants:
          Fuel Gas                                             =  1.0000E+00
          O2                                                   =  1.3558E+00
        Products:
          CO2                                                  =  9.3953E-01
          H2O                                                  =  1.1267E+00
      Reaction (NO reburn) : Reburn NO Fuel Gas PDF
        Reactants:
          Fuel Gas                                             =  3.6879E-01
          NO                                                   =  1.0000E+00
        Products:
          CO2                                                  =  3.4648E-01
          H2O                                                  =  4.1552E-01
          N2                                                   =  5.0000E-01
      +--------------------------------------------------------------------+
      |                   Autocomputed Mass Coefficients                   |
      +--------------------------------------------------------------------+
      Reaction (devolatilisation) : HC Fuel Devolat HCN
        Reactants:
          HC Fuel.Raw Combustible                              =  1.0000E+00
        Products:
          Gas Mixture HCN NO.Fuel Gas                          =  5.0003E-01
          Gas Mixture HCN NO.HCN                               =  1.1857E-02
          HC Fuel.Char                                         =  4.8812E-01
      Reaction (char oxidation) : HC Fuel Char Gibb HCN
        Reactants:
          Gas Mixture HCN NO.O2                                =  2.6049E+00
          HC Fuel.Char                                         =  1.0000E+00
        Products:
          Gas Mixture HCN NO.CO2                               =  3.5817E+00
          Gas Mixture HCN NO.HCN                               =  2.3164E-02

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