Summary for: SlidingAirgapBase < handle

Class summary

SlidingAirgapBase Base class for airgaps.

Base class for handling motion via a sliding interface. An airgap class is responsible for generating a layered airgap mesh, and computing airgap matrices without introducing extra degrees of freedom (Lagrange multipliers) to the problem.

** IMPORTANT: Most base classes assume that the base meshes of the geometries are suitably aligned, i.e. origin-centric and the clock-wise boundary at y=0 for radial flux machines, and extending from x=0 towards the negative direction for linear/axial flux machines. Geometry features such as skewing, biasing, multiple slices of geometry not aligned as described above must be handled by different means; the recommended approach is manipulating the airgap matrix, torque computation, airgap plotting, and geometry plotting interfaces in the MotorModelBase subclass, see the RFModelWithSkew class for a comprehensive example.

Properties

.SlidingAirgapBase/P_fixed is a property.

.SlidingAirgapBase/Sconst is a property.

.SlidingAirgapBase/Sint is a property.

.SlidingAirgapBase/angle_multiplier is a property.

.interpolation_method Interpolation method to use.

Options include ‘lagrange’, ‘spline’, and ‘trigonometric’.

Setting ‘legacy’ reverts to legacy 3rd-order Lagrange interpolation, with some differences in the implementation.

.interpolation_order Interpolation order-like.

The order of interpolation order, or like, to be used when computing the continuity conditions for the sliding interface.

The potential of each node on the moving side will depend on the potential of interpolation_order + 1 nodes on the static side.

.SlidingAirgapBase/is_constant is a property.

.SlidingAirgapBase/le_fixed is a property.

.SlidingAirgapBase/le_fixed_single is a property.

.SlidingAirgapBase/le_int is a property.

.SlidingAirgapBase/model is a property.

.SlidingAirgapBase/moving_component is a property.

.SlidingAirgapBase/n_bnd_moving is a property.

.SlidingAirgapBase/n_bnd_static is a property.

.SlidingAirgapBase/n_fixed is a property.

.SlidingAirgapBase/n_int is a property.

.SlidingAirgapBase/r_int is a property.

.SlidingAirgapBase/static_component is a property.

.SlidingAirgapBase/t_fixed is a property.

.SlidingAirgapBase/t_int is a property.

Methods

Class methods are listed below. Inherited methods are not included.

.compute_airgap_flux_density_data Compute airgap flux density data

Bdata = compute_airgap_flux_density_data(this, solution, step) computes the airgap flux density struct Bdata, from the given MagneticsSolution at the given time-step. The output struct contains the following fields:

  • plot_coordinates : Coordinates (tangential coordinates in the gap frame) at which the flux density has been computed.
  • Bn : normal component of the flux density
  • Bt : tangential component of the flux density
  • Bn_spectrum : spectrum of the normal component, computed with fft.
  • normal_position = position at which results are plotted
  • cdata : gap key dimensions

The following key-value pairs are supported:

  • number_of_points : number of evaluation points. Defaults to 1000.
  • relative_position : relative position within the airgap, at which to evaluate the flux density. A position of 0 corresponds to the surface of the static component, with 1 corresponding to the moving component. Defaults to 0.5 = center of airgap.

.SlidingAirgapBase/compute_stiffness_matrices is a function.

compute_stiffness_matrices(this)

.compute_torque Torque computation method.

[Torque, Force] = compute_torque(this, solution)

.drawFluxLines Draws flux lines.

drawFluxLines(msh, A, Nl, args) draws a total of Nl flux lines with the “plot” function and input arguments args

If the mesh struct msh has a field “rotel”, the call syntax can be drawFluxLines(msh, A, Nl, rotorAngle, args)

Copyright (c) 2016 Antti Lehikoinen / Aalto University

.SlidingAirgapBase/evaluate_interpolant is a function.

[I, J, E] = evaluate_interpolant(this, rotorAngle)

.SlidingAirgapBase/fluxplot is a function.

fluxplot(this, A, rotorAngle, potentials)

.gap_coordinates_to_cartesian Transform coordinates

[x, y] = gap_coordinates_to_cartesian(this, n, t) transforms the coordinates in the gap (normal, tangential) frame to the global Cartesian frame

.SlidingAirgapBase/get_airgap_meshes is a function.

[msh_static, msh_moving] = get_airgap_meshes(this)

.get_interpolatedMatrix Get interpolated matrix.

[Sag, P] = get_interpolatedMatrix(this, rotorAngle) returns the non-constant part of the airgap matrix for the given rotor angular position, along with the interpolation matrix P.

The interpolation matrix is computed with this.evaluate_interpolant

.get_key_dimensions Return key airgap dimensions

data = get_key_dimensions(this) returns a struct of the key airgap dimensions, with the following fields

  • length : average airgap length
  • static_side_coordinate : average normal coordinate (see below) of the static side of the airgap
  • moving_side_coordinate : average normal coordinate of the the moving side of the airgap
  • interface_coordinate : average normal coordinate for the sliding interface
  • maximum_tangential_coordinate : maximum (absolute) coordinate along the tangential axis of the gap
  • coordinate_labels = a 1x2 string array for the labels of the normal and tangential coordinate axes.

For example, the (radius, angle) coordinate pair would be expected for a radial-flux-type gap, and e.g. (y,x) could be the output for a linear gap.

.transform_force_to_stationary_frame Force transformation.

Fxy = transform_force_to_stationary_frame(this, F, rotor_angle) transforms the force F from rotor coordinates (rotor at angle rotor_angle (mech. rad)) to stator coordinates.

.TRIPLOT Plots a 2D triangulation

TRIPLOT(TRI,X,Y) displays the triangles defined in the M-by-3 matrix TRI. A row of TRI contains indices into X,Y that define a single triangle. The default line color is blue.

TRIPLOT(TR) displays the triangles in the triangulation TR.

TRIPLOT(…,COLOR) uses the string COLOR as the line color.

H = TRIPLOT(…) returns a line handle representing the displayed triangles edges.

TRIPLOT(…,’param’,’value’,’param’,’value’…) allows additional line param/value pairs to be used when creating the plot.

Example 1: X = rand(10,2); dt = delaunayTriangulation(X); triplot(dt)

Example 2: % Plotting a Delaunay triangulation in face-vertex format X = rand(10,2); dt = delaunayTriangulation(X); tri = dt(:,:); triplot(tri, X(:,1), X(:,2));

See also TRISURF, TRIMESH, DELAUNAY, triangulation, delaunayTriangulation.

.SlidingAirgapBase/update_rotor_position is a function.

update_rotor_position(this, rotorAngle, t)

.vector_to_gap_coordinates Transform vector

[Brad, Btan] = vector_to_gap_coordinates(~, x, y, vx, vy) transforms the given vector (vx, vy) into the airgap (normal, tangential) coordinates