FELiCS.Equation.Reactions.TwoStepReaction

FELiCS.Equation.Reactions.TwoStepReaction#

Module Contents#

Classes#

TwoStepReaction

Represents a two-step methane-air combustion reaction mechanism.
class FELiCS.Equation.Reactions.TwoStepReaction.TwoStepReaction(ModelName)#

Represents a two-step methane-air combustion reaction mechanism.

This class models two-step chemical reactions, adapted for BFER or 2S_CH4_CM2 models, and provides methods for reading reaction data, computing mean fields, and evaluating reaction rates. See CERFACS for model reference https://www.cerfacs.fr/cantera/mechanisms/meth.php

Initialize the TwoStepReaction object

Parameters:

ModelName (str) – Name of the reaction model to use.

Variables:

  • mixtureDirectory (str) – Directory name for mixture data.

  • speciesDirectory (str) – Directory name for species data.

  • p0 (float) – Reference pressure.

  • R (float) – Universal gas constant.

  • n_CH4_1 (float or None) – Stoichiometric prefactor for CH4 in reaction 1.

  • n_O2_1 (float or None) – Stoichiometric prefactor for O2 in reaction 1.

  • n_CO_1 (float or None) – Stoichiometric prefactor for CO in reaction 1.

  • n_CO_2 (float or None) – Stoichiometric prefactor for CO in reaction 2.

  • n_O2_2 (float or None) – Stoichiometric prefactor for O2 in reaction 2.

  • n_CO2_2 (float or None) – Stoichiometric prefactor for CO2 in reaction 2.

  • nu_CH4_1 (float or None) – Kinematic exponent for CH4 in reaction 1.

  • nu_O2_1 (float or None) – Kinematic exponent for O2 in reaction 1.

  • nu_CO_2 (float or None) – Kinematic exponent for CO in reaction 2.

  • nu_O2_2 (float or None) – Kinematic exponent for O2 in reaction 2.

  • nu_CO2_2 (float or None) – Kinematic exponent for CO2 in reaction 2.

  • A1 (float or None) – Pre-exponential factor for reaction 1.

  • Ta1 (float or None) – Activation temperature for reaction 1.

  • beta1 (float or None) – Temperature exponent for reaction 1.

  • h1 (float or None) – Heat of reaction for reaction 1.

  • A2 (float or None) – Pre-exponential factor for reaction 2.

  • Ta2 (float or None) – Activation temperature for reaction 2.

  • beta2 (float or None) – Temperature exponent for reaction 2.

  • h2 (float or None) – Heat of reaction for reaction 2.

  • WO2 (float or None) – Molar mass of O2.

  • WH2O (float or None) – Molar mass of H2O.

  • WCH4 (float or None) – Molar mass of CH4.

  • WCO (float or None) – Molar mass of CO.

  • WCO2 (float or None) – Molar mass of CO2.

  • WN2 (float or None) – Molar mass of N2.

  • Q1 (object or None) – Reaction progress rate for reaction 1.

  • Q2f (object or None) – Forward reaction progress rate for reaction 2.

  • Q2r (object or None) – Reverse reaction progress rate for reaction 2.

  • Q2 (object or None) – Total reaction progress rate for reaction 2.

  • K2f (object or None) – Forward reaction rate constant for reaction 2.

  • K2r (object or None) – Reverse reaction rate constant for reaction 2.

  • lnexpInEqui_h (object or None) – Linearized enthalpy term for equilibrium constant in reaction 2.

  • expInEqui (object or None) – Exponential term for equilibrium constant in reaction 2.

  • Equi (object or None) – Equilibrium constant for reaction 2.

  • i_rho (int or None) – Index for density in solution variables.

  • i_CH4 (int or None) – Index for CH4 in solution variables.

  • i_O2 (int or None) – Index for O2 in solution variables.

  • i_CO2 (int or None) – Index for CO2 in solution variables.

  • i_CO (int or None) – Index for CO in solution variables.

  • T (object or None) – Temperature field.

  • Y_CH4_limited (object or None) – Limited CH4 mass fraction.

  • epsilon (float) – Correction for base flow CH4.

  • reactionName (str) – Name of the reaction.

ReadReactionDict(ModelName)#

Reads reaction parameters and species data from files and updates class attributes.

Parameters:

ModelName (str) – Name of the reaction model to use.

Notes

This method sets stoichiometric prefactors, kinematic exponents, reaction constants, and molar masses based on the provided model name.

computeMeanField(MF, ele)#

Computes the mean field reaction rates and equilibrium constants.

Parameters:

  • MF (dict) – Dictionary containing mean flow properties.

  • ele (dolfinx.fem.FunctionSpace) – Function space for interpolation.

Returns:

  • Q1 (object) – Mean field for reaction 1.

  • Q2f (object) – Forward mean field for reaction 2.

  • Q2r (object) – Reverse mean field for reaction 2.

Notes

This method also computes equilibrium constants and related fields for reaction 2.

addReaction(MF, testf, trialf, solutionList, ele)#

Adds the reaction terms to the weak form for both reaction steps.

Parameters:

  • MF (dict) – Dictionary containing mean flow properties.

  • testf (list) – List of test functions.

  • trialf (dict) – Dictionary of trial functions.

  • solutionList (list of str) – List of solution variable names.

  • ele (dolfinx.fem.FunctionSpace) – Function space for interpolation.

Returns:

reaction_term – Weak form expression representing the reaction contributions.

Return type:

ufl.Form

Notes

The method computes the indices for relevant variables and constructs the weak form using the reaction rates and heat release for both steps.

dQ1_(MF, trialf)#

Computes the fluctuation of the reaction rate for the first reaction step.

Parameters:

  • MF (dict) – Dictionary containing mean flow properties.

  • trialf (dict) – Dictionary of trial functions.

Returns:

dQ1 – Fluctuation of the reaction rate for reaction 1.

Return type:

float

dQ2f_(MF, trialf)#

Computes the fluctuation of the forward reaction rate for the second reaction step.

Parameters:

  • MF (dict) – Dictionary containing mean flow properties.

  • trialf (dict) – Dictionary of trial functions.

Returns:

dQ2f – Fluctuation of the forward reaction rate for reaction 2.

Return type:

float

dQ2r_(MF, trialf)#

Computes the fluctuation of the reverse reaction rate for the second reaction step.

Parameters:

  • MF (dict) – Dictionary containing mean flow properties.

  • trialf (dict) – Dictionary of trial functions.

Returns:

dQ2r – Fluctuation of the reverse reaction rate for reaction 2.

Return type:

float

dK2fdT_(T)#

Computes the temperature derivative of the forward reaction rate constant for reaction 2.

Parameters:

T (object) – Temperature field.

Returns:

dK2fdT – Expression for the temperature derivative of the forward rate constant.

Return type:

object

dK2rdT_(T)#

Computes the temperature derivative of the reverse reaction rate constant for reaction 2.

Parameters:

T (object) – Temperature field.

Returns:

dK2rdT – Expression for the temperature derivative of the reverse rate constant.

Return type:

object

dEquidT_(T)#

Computes the temperature derivative of the equilibrium constant for reaction 2.

Parameters:

T (object) – Temperature field.

Returns:

dEquidT – Expression for the temperature derivative of the equilibrium constant.

Return type:

object

dexpInEquidT_(T)#

Computes the temperature derivative of the exponential part of the equilibrium constant for reaction 2.

Parameters:

T (object) – Temperature field.

Returns:

dexpInEquidT – Expression for the temperature derivative of the exponential part of the equilibrium constant.

Return type:

object

postHeatRelaese(MF, prho, pCH4, pO2, pCO, pCO2, ele)#

Evaluates the fluctuation of heat release in post-processing.

Parameters:

  • MF (dict) – Dictionary containing mean flow properties.

  • prho (float) – Perturbation in density.

  • pCH4 (float) – Perturbation in CH4 mass fraction.

  • pO2 (float) – Perturbation in O2 mass fraction.

  • pCO (float) – Perturbation in CO mass fraction.

  • pCO2 (float) – Perturbation in CO2 mass fraction.

  • ele (dolfinx.fem.FunctionSpace) – Function space for interpolation.

Returns:

heat_release_field – Projected fluctuation heat release field.

Return type:

object

postdQ1_(MF, prho, pO2, pCH4, ele)#

Computes the fluctuation of the reaction rate for the first reaction step in post-processing.

Parameters:

  • MF (dict) – Dictionary containing mean flow properties.

  • prho (float) – Perturbation in density.

  • pO2 (float) – Perturbation in O2 mass fraction.

  • pCH4 (float) – Perturbation in CH4 mass fraction.

  • ele (dolfinx.fem.FunctionSpace) – Function space for interpolation.

Returns:

dQ1 – Fluctuation of the reaction rate for reaction 1.

Return type:

float

postdQ2f_(MF, prho, pCO, pO2)#

Computes the fluctuation of the forward reaction rate for the second reaction step in post-processing.

Parameters:

  • MF (dict) – Dictionary containing mean flow properties.

  • prho (float) – Perturbation in density.

  • pCO (float) – Perturbation in CO mass fraction.

  • pO2 (float) – Perturbation in O2 mass fraction.

Returns:

dQ2f – Fluctuation of the forward reaction rate for reaction 2.

Return type:

float

postdQ2r_(MF, prho, pCO2)#

Computes the fluctuation of the reverse reaction rate for the second reaction step in post-processing.

Parameters:

  • MF (dict) – Dictionary containing mean flow properties.

  • prho (float) – Perturbation in density.

  • pCO2 (float) – Perturbation in CO2 mass fraction.

Returns:

dQ2r – Fluctuation of the reverse reaction rate for reaction 2.

Return type:

float

testM()#

Prints the maximum reaction rates of the base flow for diagnostic purposes.

Notes

This method outputs the maximum values of reaction rates for reaction 1, reaction 2 forward, and reaction 2 inverse.

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