Xmpl3d31, 31st 'example' data file for CPO3D

Field at a circular hole in an infinite flat sheet.

The file was written when the memory and speed of PC's was much more limited than at present, so the available number of segments was small and the requested inaccuracies were fairly high to give a quick demonstration.

This is a 2-dimensional problem and so can be dealt with more accurately using CPO2D -see test2d15.

See test2d15 for a description of the geometry.

The data file above gives a total of 142 segments, and simulates outer screening cylinders of radius 5 and length 10.

For greater accuracy the subdivision numbers in the azimuthal direction are all doubled and the outer radius and length are increased to 10 and 20 respectively (and also the number of radial subdivisions in the outermost part of the central disc is increased from 2 to 3). This gives a total of 292 segments.

For even better accuracy all the subdivision numbers in the radial direction are then doubled, and the subdivision at the edge becomes 64 azimuthal divisions from r = 1 to 1.01 and 32 from 1.01 to 1.03, giving a total of 648 segments.

Collected results for potentials p and fields e:

segs p at z = e at z =

-1 0 1 -1 0 1

142 |
.06937 |
.3196 |
1.068 |
.0912 |
.4992 |
.9074 |

292 |
.0684 |
.3190 |
1.068 |
.0916 |
.4996 |
.9076 |

648 |
.0686 |
.3186 |
1.068 |
.0909 |
.4997 |
.9086 |

exact |
.0683 |
.3183 |
1.068 |
.0909 |
.5000 |
.9092 |