rmgpy.kinetics.PDepArrhenius¶

class
rmgpy.kinetics.
PDepArrhenius
(pressures=None, arrhenius=None, highPlimit=None, Tmin=None, Tmax=None, Pmin=None, Pmax=None, comment='')¶ A kinetic model of a phenomenological rate coefficient \(k(T,P)\) where a set of Arrhenius kinetics are stored at a variety of pressures and interpolated between on a logarithmic scale. The attributes are:
Attribute Description pressures The list of pressures arrhenius The list of Arrhenius
objects at each pressureTmin The minimum temperature in K at which the model is valid, or zero if unknown or undefined Tmax The maximum temperature in K at which the model is valid, or zero if unknown or undefined Pmin The minimum pressure in bar at which the model is valid, or zero if unknown or undefined Pmax The maximum pressure in bar at which the model is valid, or zero if unknown or undefined efficiencies A dict associating chemical species with associated efficiencies order The reaction order (1 = first, 2 = second, etc.) comment Information about the model (e.g. its source) The pressuredependent Arrhenius formulation is sometimes used to extend the Arrhenius expression to handle pressuredependent kinetics. The formulation simply parameterizes \(A\), \(n\), and \(E_\mathrm{a}\) to be dependent on pressure:
\[k(T,P) = A(P) \left( \frac{T}{T_0} \right)^{n(P)} \exp \left( \frac{E_\mathrm{a}(P)}{RT} \right)\]Although this suggests some physical insight, the \(k(T,P)\) data is often highly complex and nonArrhenius, limiting the usefulness of this formulation to simple systems.

Pmax
¶ The maximum pressure at which the model is valid, or
None
if not defined.

Pmin
¶ The minimum pressure at which the model is valid, or
None
if not defined.

Tmax
¶ The maximum temperature at which the model is valid, or
None
if not defined.

Tmin
¶ The minimum temperature at which the model is valid, or
None
if not defined.

arrhenius
¶ arrhenius – list

changeRate
(self, double factor)¶ Changes kinetics rate by a multiple
factor
.

comment
¶ comment – str

discrepancy
(self, KineticsModel otherKinetics) → double¶ Returns some measure of the discrepancy based on two different reaction models.

efficiencies
¶ efficiencies – dict

fitToData
(self, ndarray Tlist, ndarray Plist, ndarray K, str kunits, double T0=1)¶ Fit the pressuredependent Arrhenius model to a matrix of rate coefficient data K with units of kunits corresponding to a set of temperatures Tlist in K and pressures Plist in Pa. An Arrhenius model is fit cpdef changeRate(self, double factor)at each pressure.

getCanteraEfficiencies
(self, speciesList)¶ Returns a dictionary containing the collider efficiencies for this PDepKineticsModel object suitable for setting the efficiencies in the following cantera reaction objects: ThreeBodyReaction, FalloffReaction,`ChemicallyActivatedReaction`

getEffectiveColliderEfficiencies
(self, list species) → ndarray¶ Return the effective collider efficiencies for all species in the form of a numpy array. This function helps assist rapid effective pressure calculations in the solver.

getEffectivePressure
(self, double P, list species, ndarray fractions) → double¶ Return the effective pressure in Pa for a system at a given pressure P in Pa composed of the given list of species (Species or Molecule objects) with the given fractions.

getRateCoefficient
(self, double T, double P=0) → double¶ Return the rate coefficient in the appropriate combination of m^3, mol, and s at temperature T in K and pressure P in Pa.

highPlimit
¶ highPlimit – rmgpy.kinetics.model.KineticsModel

isIdenticalTo
(self, KineticsModel otherKinetics) → bool¶ Returns
True
if kinetics matches that of another kinetics model. Each duplicate reaction must be matched and equal to that in the other PDepArrhenius model in the same order. Otherwise returnsFalse

isPressureDependent
(self) → bool¶ Return
True
since all objects derived from PDepKineticsModel represent pressuredependent kinetics.

isPressureValid
(self, double P) → bool¶ Return
True
if the pressure P in Pa is within the valid pressure range of the kinetic data, orFalse
if not. If the minimum and maximum pressure are not defined,True
is returned.

isSimilarTo
(self, KineticsModel otherKinetics) → bool¶ Returns
True
if rates of reaction at temperatures 500,1000,1500,2000 K and 1 and 10 bar are within +/ .5 for log(k), in other words, within a factor of 3.

isTemperatureValid
(self, double T) → bool¶ Return
True
if the temperature T in K is within the valid temperature range of the kinetic data, orFalse
if not. If the minimum and maximum temperature are not defined,True
is returned.

pressures
¶ The list of pressures.

setCanteraKinetics
(self, ctReaction, speciesList)¶ Sets a Cantera PlogReaction()’s rates attribute with A list of tuples containing [(pressure in Pa, cantera arrhenius object), (..)]

toHTML
(self)¶ Return an HTML rendering.
