The 1- or 2-parameter Tsang falloff parameterization. More...

#include <Falloff.h>

Inheritance diagram for TsangRate:

Collaboration diagram for TsangRate:

Public Member Functions
	TsangRate ()
	Constructor. More...

	TsangRate (const AnyMap &node, const UnitStack &rate_units={})

	TsangRate (const ArrheniusRate &low, const ArrheniusRate &high, const vector_fp &c)

unique_ptr< MultiRateBase >	newMultiRate () const
	Create a rate evaluator for reactions of a particular derived type. More...

virtual void	setFalloffCoeffs (const vector_fp &c)
	Set coefficients used by parameterization. More...

virtual void	getFalloffCoeffs (vector_fp &c) const
	Retrieve coefficients of the falloff parameterization. More...

virtual void	updateTemp (double T, double *work) const
	Update the temperature parameters in the representation. More...

virtual double	F (double pr, const double *work) const
	The falloff function. More...

virtual size_t	workSize () const
	The size of the work array required. More...

virtual const std::string	type () const
	String identifying reaction rate specialization. More...

virtual size_t	nParameters () const
	Returns the number of parameters used by this parameterization. More...

virtual void	setParameters (const AnyMap &node, const UnitStack &rate_units)
	Set parameters. More...

virtual void	getParameters (double *params) const
	Sets params to contain, in order,. More...

virtual void	getParameters (AnyMap &node) const
	Get parameters. More...

Public Member Functions inherited from FalloffRate
	FalloffRate (const AnyMap &node, const UnitStack &rate_units={})

void	init (const vector_fp &c)
	Initialize. More...

double	evalF (double T, double conc3b)
	Evaluate falloff function at current conditions. More...

virtual double	evalFromStruct (const FalloffData &shared_data)
	Evaluate reaction rate. More...

void	check (const std::string &equation, const AnyMap &node)
	Check basic syntax and settings of reaction rate expression. More...

virtual void	validate (const std::string &equation, const Kinetics &kin)
	Validate the reaction rate expression. More...

bool	allowNegativePreExponentialFactor () const
	Get flag indicating whether negative A values are permitted. More...

void	setAllowNegativePreExponentialFactor (bool value)
	Set flag indicating whether negative A values are permitted. More...

bool	chemicallyActivated () const
	Get flag indicating whether reaction is chemically activated. More...

void	setChemicallyActivated (bool activated)
	Set flag indicating whether reaction is chemically activated. More...

ArrheniusRate &	lowRate ()
	Get reaction rate in the low-pressure limit. More...

void	setLowRate (const ArrheniusRate &low)
	Set reaction rate in the low-pressure limit. More...

ArrheniusRate &	highRate ()
	Get reaction rate in the high-pressure limit. More...

void	setHighRate (const ArrheniusRate &high)
	Set reaction rate in the high-pressure limit. More...

Public Member Functions inherited from ReactionRate
	ReactionRate (const ReactionRate &other)

ReactionRate &	operator= (const ReactionRate &other)

AnyMap	parameters () const
	Return the parameters such that an identical Reaction could be reconstructed using the newReaction() function. More...

virtual void	validate (const std::string &equation)
	Validate the reaction rate expression (legacy call) More...

size_t	rateIndex () const
	Reaction rate index within kinetics evaluator. More...

void	setRateIndex (size_t idx)
	Set reaction rate index within kinetics evaluator. More...

virtual void	setContext (const Reaction &rxn, const Kinetics &kin)
	Set context of reaction rate evaluation. More...

double	eval (double T)
	Evaluate reaction rate based on temperature. More...

double	eval (double T, double extra)
	Evaluate reaction rate based on temperature and an extra parameter. More...

double	eval (double T, const std::vector< double > &extra)
	Evaluate reaction rate based on temperature and an extra vector parameter. More...

Protected Attributes
double	m_a
	parameter a in the Tsang F_cent formulation. Dimensionless More...

double	m_b
	parameter b in the Tsang F_cent formulation. [K^-1] More...

Protected Attributes inherited from FalloffRate
ArrheniusRate	m_lowRate
	The reaction rate in the low-pressure limit. More...

ArrheniusRate	m_highRate
	The reaction rate in the high-pressure limit. More...

bool	m_chemicallyActivated
	Flag labeling reaction as chemically activated. More...

bool	m_negativeA_ok
	Flag indicating whether negative A values are permitted. More...

double	m_rc_low
	Evaluated reaction rate in the low-pressure limit. More...

double	m_rc_high
	Evaluated reaction rate in the high-pressure limit. More...

vector_fp	m_work
	Work vector. More...

Protected Attributes inherited from ReactionRate
AnyMap	m_input
	Input data used for specific models. More...

size_t	m_rate_index
	Index of reaction rate within kinetics evaluator. More...

Additional Inherited Members

Detailed Description

The 1- or 2-parameter Tsang falloff parameterization.

The Tsang falloff model is adapted from that of Troe. It provides a constant or linear in temperature value for \( F_{cent} \):

\[ F_{cent} = A + B*T \]

The value of \( F_{cent} \) is then applied to Troe's model for the determination of the value of \( F \):

\[ F = F_{cent}^{1/(1 + f_1^2)} \]

where

\[ f_1 = (\log_{10} P_r + C) / \left(N - 0.14 (\log_{10} P_r + C)\right) \]

\[ C = -0.4 - 0.67 \log_{10} F_{cent} \]

\[ N = 0.75 - 1.27 \log_{10} F_{cent} \]

References: Example of reaction database developed by Tsang utilizing this format: https://doi.org/10.1063/1.555890 Example of Chemkin implementation of Tsang format (supplemental materials): https://doi.org/10.1016/j.combustflame.2011.02.010

Definition at line 546 of file Falloff.h.

Constructor & Destructor Documentation

◆ TsangRate() [1/3]

TsangRate ( )

inline

Constructor.

Definition at line 550 of file Falloff.h.

References FalloffRate::m_work.

◆ TsangRate() [2/3]

TsangRate	(	const AnyMap &	node,
		const UnitStack &	rate_units = `{}`
	)

inline

Definition at line 554 of file Falloff.h.

◆ TsangRate() [3/3]

TsangRate	(	const ArrheniusRate &	low,
		const ArrheniusRate &	high,
		const vector_fp &	c
	)

inline

Definition at line 560 of file Falloff.h.

Member Function Documentation

◆ newMultiRate()

unique_ptr< MultiRateBase > newMultiRate ( ) const

inlinevirtual

Create a rate evaluator for reactions of a particular derived type.

Derived classes usually implement this as:

unique_ptr<MultiRateBase> newMultiRate() const override {

return unique_ptr<MultiRateBase>(new MultiRate<RateType, DataType>);

Cantera::TsangRate::newMultiRate

unique_ptr< MultiRateBase > newMultiRate() const

Create a rate evaluator for reactions of a particular derived type.

Definition: Falloff.h:568

where RateType is the derived class name and DataType is the corresponding container for parameters needed to evaluate reactions of that type.

Reimplemented from ReactionRate.

Definition at line 568 of file Falloff.h.

◆ setFalloffCoeffs()

void setFalloffCoeffs ( const vector_fp & c )

virtual

Set coefficients used by parameterization.

Parameters

c	Vector of one or two doubles: The doubles are the parameters, a and (optionally) b of the Tsang F_cent parameterization

Reimplemented from FalloffRate.

Definition at line 444 of file Falloff.cpp.

◆ getFalloffCoeffs()

void getFalloffCoeffs ( vector_fp & c ) const

virtual

Retrieve coefficients of the falloff parameterization.

Parameters

c	Vector of coefficients of the parameterization. The number and meaning of these coefficients is subclass-dependent.

Reimplemented from FalloffRate.

Definition at line 461 of file Falloff.cpp.

References Cantera::SmallNumber.

◆ updateTemp()

void updateTemp	(	double	T,
		double *	work
	)		const

virtual

Update the temperature parameters in the representation.

Parameters

T	Temperature (Kelvin)
work	Vector of working space, length 1, representing the temperature-dependent part of the parameterization.

Reimplemented from FalloffRate.

Definition at line 470 of file Falloff.cpp.

◆ F()

double F	(	double	pr,
		const double *	work
	)		const

virtual

The falloff function.

This is defined so that the rate coefficient is

\[ k = F(Pr)\frac{Pr}{1 + Pr}. \]

Here \( Pr \) is the reduced pressure, defined by

\[ Pr = \frac{k_0 [M]}{k_\infty}. \]

Parameters

pr	reduced pressure (dimensionless).
work	array of size workSize() containing cached temperature-dependent intermediate results from a prior call to updateTemp.

Returns: the value of the falloff function \( F \) defined above

Reimplemented from FalloffRate.

Definition at line 476 of file Falloff.cpp.

◆ workSize()

virtual size_t workSize ( ) const

inlinevirtual

The size of the work array required.

Todo:: deprecate; only used by legacy framework

Reimplemented from FalloffRate.

Definition at line 591 of file Falloff.h.

◆ type()

virtual const std::string type ( ) const

inlinevirtual

String identifying reaction rate specialization.

Reimplemented from FalloffRate.

Definition at line 595 of file Falloff.h.

◆ nParameters()

virtual size_t nParameters ( ) const

inlinevirtual

Returns the number of parameters used by this parameterization.

The values of these parameters can be obtained from getParameters().

Reimplemented from FalloffRate.

Definition at line 599 of file Falloff.h.

◆ setParameters()

void setParameters	(	const AnyMap &	node,
		const UnitStack &	units
	)

virtual

Set parameters.

Parameters

node	AnyMap object containing reaction rate specification
units	unit definitions specific to rate information

Reimplemented from FalloffRate.

Definition at line 486 of file Falloff.cpp.

References AnyMap::empty().

◆ getParameters() [1/2]

void getParameters ( double * params ) const

virtual

Sets params to contain, in order,.

\[ (A, B) \]

Todo:: deprecate; superseded by getFalloffCoeffs

Reimplemented from FalloffRate.

Definition at line 504 of file Falloff.cpp.

◆ getParameters() [2/2]

void getParameters ( AnyMap & node ) const

virtual

Get parameters.

Parameters

node	AnyMap containing rate information Store the parameters of a ReactionRate needed to reconstruct an identical object. Does not include user-defined fields available in the m_input map.

Reimplemented from FalloffRate.

Definition at line 509 of file Falloff.cpp.

References AnyMap::setFlowStyle().

Member Data Documentation

◆ m_a

double m_a

protected

parameter a in the Tsang F_cent formulation. Dimensionless

Definition at line 615 of file Falloff.h.

◆ m_b

double m_b

protected

parameter b in the Tsang F_cent formulation. [K^-1]

Definition at line 618 of file Falloff.h.

The documentation for this class was generated from the following files:

Public Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ TsangRate() [1/3]

◆ TsangRate() [2/3]

◆ TsangRate() [3/3]

Member Function Documentation

◆ newMultiRate()

◆ setFalloffCoeffs()

◆ getFalloffCoeffs()

◆ updateTemp()

◆ F()

◆ workSize()

◆ type()

◆ nParameters()

◆ setParameters()

◆ getParameters() [1/2]

◆ getParameters() [2/2]

Member Data Documentation

◆ m_a

◆ m_b