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Nr 5: Coilend Types

Goal

Demonstrate the different variants of 3D coil ends as well as helical coils, 2D and 3D preview.

Description

  • Block Data 2D & 3D: In 3D calculations, the last column in the Block Data 2D table points to a coilend definition. One definition may serve for several 2D blocks (see blocks 5-7 and 8-10).
  • Constant Perim. f: Constant perimeter coil ends are determined by equal lengthes (perimeters) of the upper and lower edge of the conductor in the coil end. In ROXIE, a total of 8 lines covers the conductor including the lower to the upper edge. The minimum squeeze and maximum stretch of the cable is computed by the ratios of the different lengths of these lines. An ideal constant-perimeter end should have min squeeze = max stretch = 1. The 'f' definition of the end describes the so-called ellipse on cylinder by the radial position of the cable in the cross-section and an ellipticity.
  • Constant Perim. B: The 'B' definition of the constant perimeter end describes the ellipse on a cylinder by the radial position of the cable in the cross-section and the longitudinal half axis B. In the 2D Preview window, YZ-section, the z-position of the upper left corner of a block is given by B0 + Z0. This numeric control of the z-positioning makes the B-version a practical option in some circumstances.
  • Constant Perim. OD: The 'OD' option can be used as the 'Constant Perim. B' option. 'OD' stands for 'outer diameter' and means that the conductors are aligned on an outer cylinder rather than on an inner mandrel. Note that the 'ODFAC' option, which lets the user control the alignment of conductors between inner and outer cylinder, works only in 2D.
  • Diff. Geometry f: This option is described in more detail in another usecase. Differential-goemetry ends are similar to constant perimeter ends, yet they yield a more accurate description of the cable as a ruled surface. The Z0 information passed to the differential geometry algorithm does not correspond precisely to the straight section dur to legacy reasons. The actual straight section length is written to the output file.
  • Hardway/Softway bend: These options must be selected in the Block 2D and Block 3D tables alike. Hardway corresponds to an inclination angle of the block of zero degrees, thus bending the cable over the narrow side. Softway corresponds to an inclination angle of 90 degrees, thus bending the cable over the wide side. In the Block Group macros it is to be noted that, e.g. a racetrack-type quadrupole formed from Softway ends corresponds to a skew quadrupole, with the first coil around the positive y-axis, and the second around the other three half-axes.
  • Racetrack: This option used to be standard for racetrack coils before the hardway- and softway-definitions. Probably the only meaningful application in version 10.1 is either to resuse old input files.
  • Twist: A straight section with an optional twist. The user can selected around which corner point the block should be twisted. Selecting 0 creates a twist around the block center.
  • Helix: There is a dedicated usecase to helices. Please note that, despite the seemless integration with other coilend types, helices are not actually coilends and many options applying to 3D coilends, e.g., in the design variables, do not apply to helices. Internally, helices are handled like additional bricks.
  • Block Groups: The block groups widget in 3-D has an additional column to choose a side (z>0 or z<0) for the coilend, or symmetric ends on both sides, or a single end z>0 with a virtual extension of the straight section to minus infinity for field computation purposes. The option 'Connection side' from the 'Type(xy)' column creates only one semi-arc per coil. The 3D plots 5 and 6 display block groups with 'Connection side' option.
  • Plotting 3D: In 3D plotting we need to specify 'COIL' to display coil ends, and 'HELIX' to display helices. With the group column we can select which block groups to plot. Zero displays all groups.

Files

use_case_5.zip

  • coilendTypes.data
  • roxie.bhdata
  • roxie.cadata