Fluxes#

Class Flux#

class multipy.flux.Flux(species_velocities)#

Supports computing and storing fluxes. This class assumes that the species velocities, \(\mathbf{u}_i\), are known.

Diffusive fluxes:

  • mass diffusive flux relative to a mass-averaged velocity, \(\mathbf{j}_i\)

  • mass diffusive flux relative to a molar-averaged velocity, \(\mathbf{j}_i^u\)

  • molar diffusive flux relative to a mass-averaged velocity, \(\mathbf{J}_i^v\)

  • molar diffusive flux relative to a molar-averaged velocity, \(\mathbf{J}_i\)

Parameters

species_velocities – vector numpy.ndarray specifying the species velocities \(\mathbf{u}_i\) in \([m/s]\). It should be of size (n_species,n_observations).

Getters:

  • get_species_velocities

  • get_diffusive_molar_molar (is set to None at class init)

  • get_diffusive_molar_mass (is set to None at class init)

  • get_diffusive_mass_molar (is set to None at class init)

  • get_diffusive_mass_mass (is set to None at class init)

Setters:

  • set_species_velocities

  • set_diffusive_molar_molar (is set to None at class init)

  • set_diffusive_molar_mass (is set to None at class init)

  • set_diffusive_mass_molar (is set to None at class init)

  • set_diffusive_mass_mass (is set to None at class init)

Flux.plot_diffusive_flux#

multipy.flux.Flux.plot_diffusive_flux(self, species_names=None, colors=None, figsize=(10, 5), filename=None)#

Plots the computed diffusive fluxes.

Example:

../_images/stefan-tube-diffusive-flux-molar-diff-molar-avg.svg
Parameters

  • species_names – (optional) list of str specifying the species names.

  • colors – (optional) list of str specifying the plotting colors for each species. Example: colors=['#C7254E', '#BBBBBB', '#008CBA'].

  • figsize – (optional) tuple specifying the figure size.

  • filename – (optional) str specifying the filename. If set to None, plot will not be saved to a file.

Flux.diffusive_molar_molar#

multipy.flux.Flux.diffusive_molar_molar(self, species_mole_fractions, species_molar_densities)#

Computes the molar diffusive flux relative to a molar-averaged velocity:

\[\mathbf{J}_i = c_i \mathbf{u}_i + c_i \mathbf{u}\]
Parameters

  • species_mole_fractions – scalar numpy.ndarray specifying the species mole fractions, \(X_i\), in \([-]\). It should be of size (n_species,n_observations).

  • species_molar_densities – scalar numpy.ndarray specifying the molar densities of species, \(c_i\), in \([mole/m^3]\). It should be of size (n_species,n_observations).

Returns

  • diffusive_flux - vector numpy.ndarray of molar diffusive fluxes relative to a molar-averaged velocity \(\mathbf{J}_i\) in \([mole/(m^2s)]\). It has size (n_species,n_observations).

Flux.diffusive_molar_mass#

multipy.flux.Flux.diffusive_molar_mass(self, species_mass_fractions, species_molar_densities)#

Computes the molar diffusive flux relative to a mass-averaged velocity:

\[\mathbf{J}_i^v = c_i \mathbf{u}_i + c_i \mathbf{v}\]
Parameters

  • species_mass_fractions – scalar numpy.ndarray specifying the species mass fractions, \(Y_i\), in \([-]\). It should be of size (n_species,n_observations).

  • species_molar_densities – scalar numpy.ndarray specifying the species molar densities \(c_i\) in \([mole/m^3]\). It should be of size (n_species,n_observations).

Returns

  • diffusive_flux - vector numpy.ndarray of molar diffusive fluxes relative to a mass-averaged velocity \(\mathbf{J}_i^v\) in \([mole/(m^2s)]\). It has size (n_species,n_observations).

Flux.diffusive_mass_molar#

multipy.flux.Flux.diffusive_mass_molar(self, species_mole_fractions, species_mass_densities)#

Computes the mass diffusive flux relative to a molar-averaged velocity:

\[\mathbf{j}_i^u = \rho_i \mathbf{u}_i + \rho_i \mathbf{u}\]
Parameters

  • species_mole_fractions – scalar numpy.ndarray specifying the species mole fractions \(X_i\) in \([-]\). It should be of size (n_species,n_observations).

  • species_mass_densities – scalar numpy.ndarray specifying the species mass densities \(\mathbf{\rho}_i\) in \([kg/m^3]\). It should be of size (n_species,n_observations).

Returns

  • diffusive_flux - vector numpy.ndarray of mass diffusive fluxes relative to a molar-averaged velocity \(\mathbf{j}_i^u\) in \([kg/(m^2s)]\). It has size (n_species,n_observations).

Flux.diffusive_mass_mass#

multipy.flux.Flux.diffusive_mass_mass(self, species_mass_fractions, species_mass_densities)#

Computes the mass diffusive flux relative to a mass-averaged velocity:

\[\mathbf{j}_i = \rho_i \mathbf{u}_i + \rho_i \mathbf{v}\]
Parameters

  • species_mass_fractions – scalar numpy.ndarray specifying the species mass fractions \(Y_i\) in \([-]\). It should be of size (n_species, n_observations).

  • species_mass_densities – scalar numpy.ndarray specifying the species mass densities \(\mathbf{\rho}_i\) in \([kg/m^3]\). It should be of size (n_species, n_observations).

Returns

  • diffusive_flux - vector numpy.ndarray of mass diffusive fluxes relative to a mass-averaged velocity \(\mathbf{j}_i\) in \([kg/(m^2s)]\). It has size (n_species, n_observations).