Cantera  2.1.2
Troe4 Class Reference

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

Inheritance diagram for Troe4:
[legend]
Collaboration diagram for Troe4:
[legend]

## Public Member Functions

Troe4 ()
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... Public Member Functions inherited from Falloff
Falloff ()
Default constructor is empty. More...

virtual ~Falloff ()
default destructor is empty More...

## Protected Attributes

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

doublereal m_rt3
parameter 1/T_3 in the 4-parameter Troe falloff function. More...

doublereal m_rt1
parameter 1/T_1 in the 4-parameter Troe falloff function. More...

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

## Detailed Description

The 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.

Definition at line 139 of file FalloffFactory.cpp.

## Constructor & Destructor Documentation

 Troe4 ( )
inline

Constructor.

Definition at line 143 of file FalloffFactory.cpp.

## Member Function Documentation

 virtual void init ( const vector_fp & c )
inlinevirtual

Initialization of the object.

Parameters
 c Vector of four doubles: The doubles are the parameters, a,, T_3, T_1, and T_2 of the Troe parameterization

Reimplemented from Falloff.

Definition at line 151 of file FalloffFactory.cpp.

References Troe4::m_a, Troe4::m_rt1, Troe4::m_rt3, and Troe4::m_t2.

 virtual void updateTemp ( doublereal T, doublereal * work ) const
inlinevirtual

Update the temperature parameters in the representation.

The workspace has a length of one

Parameters
 T Temperature (Kelvin) work Vector of working space representing the temperature dependent part of the parameterization.

Reimplemented from Falloff.

Definition at line 175 of file FalloffFactory.cpp.

References Troe4::m_a, Troe4::m_rt1, Troe4::m_rt3, Troe4::m_t2, and Cantera::SmallNumber.

 virtual doublereal F ( doublereal pr, const doublereal * work ) const
inlinevirtual

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 182 of file FalloffFactory.cpp.

References Cantera::SmallNumber.

 virtual size_t workSize ( )
inlinevirtual

The size of the work array required.

Reimplemented from Falloff.

Definition at line 192 of file FalloffFactory.cpp.

## Member Data Documentation

 doublereal m_a
protected

parameter a in the 4-parameter Troe falloff function.

This is unitless.

Definition at line 199 of file FalloffFactory.cpp.

Referenced by Troe4::init(), and Troe4::updateTemp().

 doublereal m_rt3
protected

parameter 1/T_3 in the 4-parameter Troe falloff function.

This has units of Kelvin-1.

Definition at line 203 of file FalloffFactory.cpp.

Referenced by Troe4::init(), and Troe4::updateTemp().

 doublereal m_rt1
protected

parameter 1/T_1 in the 4-parameter Troe falloff function.

This has units of Kelvin-1.

Definition at line 207 of file FalloffFactory.cpp.

Referenced by Troe4::init(), and Troe4::updateTemp().

 doublereal m_t2
protected

parameter T_2 in the 4-parameter Troe falloff function.

This has units of Kelvin.

Definition at line 211 of file FalloffFactory.cpp.

Referenced by Troe4::init(), and Troe4::updateTemp().

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