# Transport Properties¶

class cantera.Transport

Transport(*args, **kwargs)

This class is used to compute transport properties for a phase of matter.

Not all transport properties are implemented in all transport models.

CK_mode

Boolean to indicate if the chemkin interpretation is used.

binary_diff_coeffs

Binary diffusion coefficients [m^2/s].

electrical_conductivity

Electrical conductivity. [S/m].

get_binary_diff_coeffs_polynomial(self, i, j)

Get the polynomial fit to the logarithm of temperature for the binary diffusion coefficient of species i and j.

get_collision_integral_polynomials(self, i, j)

Get the polynomial fit to the logarithm of temperature for the collision integral of species i and j.

get_thermal_conductivity_polynomial(self, i)

Get the polynomial fit to the logarithm of temperature for the thermal conductivity of species i.

get_viscosity_polynomial(self, i)

Get the polynomial fit to the logarithm of temperature for the viscosity of species i.

mix_diff_coeffs

Mixture-averaged diffusion coefficients [m^2/s] relating the mass-averaged diffusive fluxes (with respect to the mass averaged velocity) to gradients in the species mole fractions.

mix_diff_coeffs_mass

Mixture-averaged diffusion coefficients [m^2/s] relating the diffusive mass fluxes to gradients in the species mass fractions.

mix_diff_coeffs_mole

Mixture-averaged diffusion coefficients [m^2/s] relating the molar diffusive fluxes to gradients in the species mole fractions.

mobilities

Electrical mobilities of charged species [m^2/s-V]

multi_diff_coeffs

Multicomponent diffusion coefficients, D[i,j], the diffusion coefficient for species i due to concentration gradients in species j [m**2/s].

set_binary_diff_coeffs_polynomial(self, i, j, values)

Set the polynomial fit to the logarithm of temperature for the binary diffusion coefficient of species i and j.

set_collision_integral_polynomial(self, i, j, avalues, bvalues, cvalues, actualT=True)

Get the polynomial fit to the logarithm of temperature for the collision integral of species i and j.

set_thermal_conductivity_polynomial(self, i, values)

Set the polynomial fit to the logarithm of temperature for the thermal conductivity of species i.

set_viscosity_polynomial(self, i, values)

Set the polynomial fit to the logarithm of temperature for the viscosity of species i.

species_viscosities

Pure species viscosities [Pa-s]

thermal_conductivity

Thermal conductivity. [W/m/K]

thermal_diff_coeffs

Return a one-dimensional array of the species thermal diffusion coefficients [kg/m/s].

transport_model

Get/Set the transport model associated with this transport model.

Setting a new transport model deletes the underlying C++ Transport object and replaces it with a new one implementing the specified model.

viscosity

Viscosity [Pa-s].

class cantera.DustyGasTransport

DustyGasTransport(*args, **kwargs)

Implements the “dusty gas” model for transport in porous media.

As implemented here, only species transport (multi_diff_coeffs) is handled. The viscosity, thermal conductivity, and thermal diffusion coefficients are not implemented.

mean_particle_diameter

Mean particle diameter of the porous medium [m].

Mean pore radius of the porous medium [m].

molar_fluxes(self, T1, T2, rho1, rho2, Y1, Y2, delta)

Get the molar fluxes [kmol/m^2/s], given the thermodynamic state at two nearby points.

Parameters
• T1 – Temperature [K] at the first point

• T2 – Temperature [K] at the second point

• rho1 – Density [kg/m^3] at the first point

• rho2 – Density [kg/m^3] at the second point

• Y1 – Array of mass fractions at the first point. Length n_species.

• Y2 – Array of mass fractions at the second point. Length n_species.

• delta – Distance [m] between the two points.

permeability

Permeability of the porous medium [m^2].

porosity

Porosity of the porous medium [dimensionless].

thermal_conductivity

Thermal conductivity. [W/m/K] Returns the thermal conductivity of the ideal gas object using the multicomponent model. The value is not specific to the dusty gas model.

tortuosity

Tortuosity of the porous medium [dimensionless].

## Species Transport Properties¶

class cantera.GasTransportData(geometry='', diameter=- 1, well_depth=- 1, dipole=0.0, polarizability=0.0, rotational_relaxation=0.0, acentric_factor=0.0, dispersion_coefficient=0.0, quadrupole_polarizability=0.0)

Bases: object

Transport data for a single gas-phase species which can be used in mixture-averaged or multicomponent transport models.

The arguments passed to the constructor are equivalent to the properties of the object, with values in MKS units. To set properties in non-MKS units, use the set_customary_units method.

acentric_factor

Get/Set Pitzer’s acentric factor. [dimensionless]

clear_user_data(self)

Clear all saved input data, so that the data given by input_data or Solution.write_yaml will only include values generated by Cantera based on the current object state.

diameter

Get/Set the Lennard-Jones collision diameter [m]

dipole

Get/Set the permanent dipole moment of the molecule [Coulomb-m].

dispersion_coefficient

Get/Set dispersion coefficient. [m^5]

geometry

Get/Set the string specifying the molecular geometry. One of atom, linear, or nonlinear.

input_data

Get input data defining this GasTransportData object, along with any user-specified data provided with its input (YAML) definition.

polarizability

Get/Set the polarizability of the molecule [m^3].

rotational_relaxation

Get/Set the rotational relaxation number (the number of collisions it takes to equilibrate the rotational degrees of freedom with the temperature).

set_customary_units(self, geometry, diameter, well_depth, dipole=0.0, polarizability=0.0, rotational_relaxation=0.0, acentric_factor=0.0, dispersion_coefficient=0.0, quadrupole_polarizability=0.0)

Set the parameters using “customary” units: diameter in Angstroms, well depth in Kelvin, dipole in Debye, and polarizability in Angstroms^3. These are the units used in in CK-style input files.

update_user_data(self, data)

Add the contents of the provided dict as additional fields when generating YAML phase definition files with Solution.write_yaml or in the data returned by input_data. Existing keys with matching names are overwritten.

well_depth

Get/Set the Lennard-Jones well depth [J]