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Nr 2: Coil Types

Goal

Demonstrate the various different 2D coil geometry types

Description

  • Block Data 2D: The lines in Block Data 2D demonstrate the different block-definition types. The difference is best visible in the plot of current density (3rd plot in the Plotting 2D).

    • The cos-theta plots are aligned on a circular mandrel. The current-density plot reveals the keystoning in the second layer, i.e., the current density is higher on the inside (narrow side) of the cable.

    • The shell-type yields sector-like blocks of cos(n)-theta current distribution. The order n of the current distribution is determined by the symmetry option in the Block Groups widget. The number of conductors determines the accuracy of the cos(n)-theta approximation. Usually this option is used to produce in an efficient way perfect n-polar field patterns. For a perfect field quality, however, the current density per conductor must be constant. To this end, the "NOGRAD" option can be selected in the "More Options" table of the Block Data 2D widget. NOGRAD means no grading, i.e., constant current density.

    • Sect-type coils are similar to shell-type coils, but have constant current distribution over the block. This option can be used in a first design phase, where the user tries to determine an approximate conductor distribution in the cross-section. At a later stage, the sector-geometry can be approximated by actual conductors.

    • Wire-type coils position conductors on a circular mandrel with a given angular spacing.

    • Rect-type definitions align the conductors on a Cartesian grid, rather than a circular mandrel.

  • Block Groups: In the block groups we select blocks from the Block Data 2D widget, group them, and apply a geometry macro. The parent-block from the Block Data 2D is duplicated (=offspring) and the duplicates are mirrored and rotated in order to yield multipolar coil assemblies.

  • Design Variables: Sometimes it is more convenient to change the shape of a conductor definition within the data-file, rather than specifying a new cable in the cadata file. For this purpose there are variables in the "2D conductor geometry and currents" section of the Design Variables' String column. The "parent and offspring" option in the "Act" column assigns a design variables to the specified blocks of the Block Data 2D, as well as on all duplicates (= offspring) that are generated by the selected Block Groups macro.

Files

use_case_2.zip

  • coilTypes.data
  • roxie.bhdata
  • roxie.cadata