Cantera  2.2.1

The 3- or 4-parameter Troe falloff parameterization. More...

#include <Falloff.h>

Inheritance diagram for Troe:
[legend]
Collaboration diagram for Troe:
[legend]

## Public Member Functions

Troe ()
Constructor. More...

virtual void init (const vector_fp &c)
Initialization of the object. More...

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

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

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

virtual int getType () const
Return an integer representing the type of the Falloff parameterization. More...

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

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

$(A, T_3, T_1, T_2)$

## Protected Attributes

doublereal m_a
parameter a in the 4-parameter Troe falloff function. Dimensionless More...

doublereal m_rt3
parameter 1/T_3 in the 4-parameter Troe falloff function. [K^-1] More...

doublereal m_rt1
parameter 1/T_1 in the 4-parameter Troe falloff function. [K^-1] More...

doublereal m_t2
parameter T_2 in the 4-parameter Troe falloff function. [K] More...

## Detailed Description

The 3- or 4-parameter Troe falloff parameterization.

The falloff function defines the value of $$F$$ in the following rate expression

$k = k_{\infty} \left( \frac{P_r}{1 + P_r} \right) F$

where

$P_r = \frac{k_0 [M]}{k_{\infty}}$

This parameterization is defined by

$F = F_{cent}^{1/(1 + f_1^2)}$

where

$F_{cent} = (1 - A)\exp(-T/T_3) + A \exp(-T/T_1) + \exp(-T_2/T)$

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

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

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

• If $$T_3$$ is zero, then the corresponding term is set to zero.
• If $$T_1$$ is zero, then the corresponding term is set to zero.
• If $$T_2$$ is zero, then the corresponding term is set to zero.

Definition at line 118 of file Falloff.h.

## Constructor & Destructor Documentation

 Troe ( )
inline

Constructor.

Definition at line 122 of file Falloff.h.

## Member Function Documentation

 void init ( const vector_fp & c )
virtual

Initialization of the object.

Parameters
 c Vector of three or four doubles: The doubles are the parameters, a, T_3, T_1, and (optionally) T_2 of the Troe parameterization

Reimplemented from Falloff.

Definition at line 22 of file Falloff.cpp.

References Cantera::int2str(), Troe::m_a, Troe::m_rt1, Troe::m_rt3, and Troe::m_t2.

 void updateTemp ( doublereal T, doublereal * 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 Falloff.

Definition at line 45 of file Falloff.cpp.

References Troe::m_a, Troe::m_rt1, Troe::m_rt3, Troe::m_t2, and Cantera::SmallNumber.

 double F ( doublereal pr, const doublereal * 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
Returns the value of the falloff function $$F$$ defined above

Reimplemented from Falloff.

Definition at line 54 of file Falloff.cpp.

References Cantera::SmallNumber.

 virtual size_t workSize ( )
inlinevirtual

The size of the work array required.

Reimplemented from Falloff.

Definition at line 141 of file Falloff.h.

 virtual int getType ( ) const
inlinevirtual

Return an integer representing the type of the Falloff parameterization.

Reimplemented from Falloff.

Definition at line 145 of file Falloff.h.

 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 Falloff.

Definition at line 149 of file Falloff.h.

 void getParameters ( double * params ) const
virtual

Sets params to contain, in order,

$(A, T_3, T_1, T_2)$

.

Reimplemented from Falloff.

Definition at line 65 of file Falloff.cpp.

References Troe::m_a, Troe::m_rt1, Troe::m_rt3, and Troe::m_t2.

## Member Data Documentation

 doublereal m_a
protected

parameter a in the 4-parameter Troe falloff function. Dimensionless

Definition at line 158 of file Falloff.h.

Referenced by Troe::getParameters(), Troe::init(), and Troe::updateTemp().

 doublereal m_rt3
protected

parameter 1/T_3 in the 4-parameter Troe falloff function. [K^-1]

Definition at line 161 of file Falloff.h.

Referenced by Troe::getParameters(), Troe::init(), and Troe::updateTemp().

 doublereal m_rt1
protected

parameter 1/T_1 in the 4-parameter Troe falloff function. [K^-1]

Definition at line 164 of file Falloff.h.

Referenced by Troe::getParameters(), Troe::init(), and Troe::updateTemp().

 doublereal m_t2
protected

parameter T_2 in the 4-parameter Troe falloff function. [K]

Definition at line 167 of file Falloff.h.

Referenced by Troe::getParameters(), Troe::init(), and Troe::updateTemp().

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