vortex_properties module

IMTreatment.vortex_properties.vortex_properties.get_vortex_circulation(VF, vort_center, epsilon=0.1, output_unit=False, verbose=False)[source]

Return the circulation of the given vortex.

$Gamma = int_S omega dS$ avec : $S$ : surface su vortex ($| omega | > epsilon$)

Recirculation is representative of the swirling strength.

Warning : integral on complex domain is complex (you don’t say?), here is just implemented a sum of accessible values on the domain.

Parameters:
  • VF (vectorfield object) – Velocity field on which compute gamma2.
  • vort_center (2x1 array) – Approximate position of the vortex center.
  • epsilon (float, optional) – Relative seuil for the vorticity integral (default is 0.1).
  • output_unit (boolean, optional) – If ‘True’, circulation unit is returned.
Returns:

circ – Vortex virculation.
Return type:

float
IMTreatment.vortex_properties.vortex_properties.get_vortex_property(VF, vort_center, size_crit=None, size_crit_lim=0.1, prop_crit=None, output_unit=False, verbose=False)[source]

Return a property of a particular vortex.

Parameters:
  • VF (vectorfield object) – Base velocity field.
  • vort_center (2x1 array) – Approximate position of the vortex center.
  • size_crit (function or 'value') – Function applied to ‘VF’ and returning a ScalarField used to get the vortex area. (Default is residual vorticity) If ‘value’, only the value at the given point is returned.
  • size_crit_lim (number) – Used to determine the size criterion interval defining the vortex area (i.e. the vortex area is the area around the vortex center where the size criterion is superior to ‘size_crit_lim’ times the value at the center) (Default is 0.1 (10%)) Useless if ‘size_crit=’value’
  • prop_crit (function) – Function applied to ‘VF’ and returning a ScalarField used to get the property value (Default is residual vorticity)
  • output_unit (boolean, optional) – If ‘True’, return the associated unit.
  • verbose (bool) – If ‘True’, display information and graph along computation.
Returns:

prop – Property associated to the vortex. (Is the integral of ‘prop_crit’ result on the area defined by ‘size_crit’)
Return type:

number
IMTreatment.vortex_properties.vortex_properties.get_vortex_property_time_evolution(TVFs, vort_center_traj, size_crit=None, size_crit_lim=0.1, prop_crit=None, output_unit=False, verbose=0)[source]

Return a property of a particular vortex.

Parameters:
  • TVFs (TemporalVectorFields object) – Base velocity fields.
  • vort_center (Points object) – Approximate position of the vortex centers along times.
  • size_crit (function or 'value') – Function applied to ‘VF’ and returning a ScalarField used to get the vortex area. (Default is residual vorticity) if ‘value’, only return the value at point.
  • size_crit_lim (number) – Used to determine the size criterion interval defining the vortex area (i.e. the vortex area is the area around the vortex center where the size criterion is superior to ‘size_crit_lim’ times the value at the center) (Default is 0.1 (10%)) Useless if “size_crit=’value”.
  • prop_crit (function) – Function applied to ‘VF’ and returning a ScalarField used to get the property value (Default is residual vorticity)
  • verbose (integer) – specified the number of fields to verbosify. Default is 0.
Returns:

prop – Evolution of the property associated with the vortex long time.
Return type:

Profile object
IMTreatment.vortex_properties.vortex_properties.get_vortex_radius(VF, vort_center, NL_radius=None, eps_detection=0.1, output_center=False, output_unit=False)[source]

Return the radius of the given vortex, use the residual vorticity.

Parameters:
  • VF (vectorfield object) – Velocity field on which compute gamma2.
  • vort_center (2x1 array) – Approximate position of the vortex center.
  • NL_radius (number, optional) – IF specified, radius used for the non-local computation of the gradients.
  • eps_detection (number) – epsilon used to determine the edge of the vortex (default is 0.1 for 10% of the maximum vorticity value).
  • output_center (boolean, optional) – If ‘True’, return the associated vortex center, computed using center of mass algorythm.
  • ; boolean, optional (output_unit) – If ‘True’, return the associated unit.
Returns:

  • radius (number) – Average radius of the vortex. If no vortex is found, 0 is returned.
  • center (2x1 array of numbers) – If ‘output_center’ is ‘True’, contain the newly computed vortex center.
  • unit_radius (Unit object) – Radius unity
IMTreatment.vortex_properties.vortex_properties.get_vortex_radius_time_evolution(TVFS, traj, NL_radius=None, eps_detection=0.1, output_center=False, verbose=False)[source]

Return the radius evolution in time for the given vortex center trajectory.

Use the criterion $|gamma2| > 2/pi$. The returned radius is an average value if the vortex zone is not circular.

Parameters:
  • TVFS (TemporalField object) – Velocity field on which compute gamma2.
  • traj (Points object) – Trajectory of the vortex.
  • NL_radius (number, optional) – IF specified, radius used for the non-local computation of the gradients.
  • eps_detection (number) – epsilon used to determine the edge of the vortex (default is 0.1 for 10% of the maximum vorticity value).
  • output_center (boolean, optional) – If ‘True’, return a Points object with associated vortex centers, computed using center of mass algorythm.
  • verbose (boolean) –

    .
Returns:

  • radius (Profile object) – Average radius of the vortex. If no vortex is found, 0 is returned.
  • center (Points object) – If ‘output_center’ is ‘True’, contain the newly computed vortex center.