Input data for a cylindrical rectangle

A rectangle on a cylindrical surface.

Caution: this is a specialised type of electrode that is not often needed -complete cylinders can usually be used instead (remember that the program will automatically allow for any symmetry planes, and cylinders can also be truncated -that is, clipped or cropped).

The user specifies:

(1) the x,y,z coordinates of the corners

(2) the radius of the parent cylinder

(3) the x,y,z coordinates of the first end of the axis of the parent cylinder

(4) the x,y,z coordinates of any other point on the axis of the parent cylinder

(5) the numbers nv1,nv2 that label the voltages that are applied to the electrode (the values of the voltages will be entered later)

-nv1 and nv2 are the same if the electrode is an equipotential

-they are different if a potential gradient is required in the z direction

(6) if nv1 and nv2 are different, then the user specifies the values of z at which these 2 voltages are applied

(7) Either:

(a) The numbers n1 and n2 of divisions along the axis and around the axis respectively.

Or (the usual recommended choice):

(b) The total number N of segments and 0. The 0 will trigger the program to partition N into n1 along the axis and n2 around the axis, in such a way that all the rectangles are as nearly square as possible. The final number of segments, n1*n2, might be slightly different from N (so if greater control is required, use n1 and n2).

For important advice on subdividing please look at section 3.4 of the Users Guide or the general advice on segmentation.

When a half cylinder is required that is cut in half by a plane through the axis, then the axis given above will lie in the plane of the corners. There is then an ambiguity in which half of cylinder is chosen by the program. If this matters and if the wrong half is chosen, then reverse the cyclic order of the corners or change the direction of the axis.

It is not possible in this program to specify a part of a cylindrical surface that is larger than one half of a cylinder (so in this case divide the required surface into two parts). The numbers of subdivisions apply to the minimum sector, before reflections in any planes of symmetry.

All types of electrodes can be scaled and/or shifted and/or reflected and/or rotated.

For users who are editing or constructing an 'input data file' without the use of the data-builder -that is, pre-processor:

But Manual editing is certainly not recommended -it is a relic from the time when the databuilder was not available All users are strongly encouraged to use the databuilder, which always gives the correct formats and which has many options for which the formats are not described or easily deduced.

Typical data for a rectangle on a cylindrical surface, taken from shap3d06.dat, are:

cre -rectangle on cylinder

0.5 0.0 -0.5 corners

0.5 0.0 0.0 deflector in +/- x direction

0.36864 0.33780 0.0

0.36864 0.33780 -0.5

0.5 radius of cylinder

0. 0. -0.5 1st point on axis

0. 0. 0.0 2nd point on axis

2 2 numbers of 2 applied voltages (can be same)

4 4 total number of subdivisions and 0, or divisions along axis and around axis

The data required are:

(1) x,y,z coordinates of corners

(2) radius -to disable the 'inscribing correction' (see the relevant note and the second relevant note), enter a negative radius

(3) x,y,z coordinates of first end of axis of parent cylinder

(4) x,y,z coordinates of any other point on axis of parent cylinder

(5) numbers nv1,nv2 that label voltages that are applied to the electrode

(6) if nv1 and nv2 are different, then enter values of z at which these 2 voltages are applied

(7) Either:

(a) The numbers n1 and n2 of divisions along the axis and around the axis respectively.

Or (the usual recommended choice):

(b) The total number N of segments and 0. The 0 will trigger the program to partition N into n1 along the axis and n2 around the axis, in such a way that all the rectangles are as nearly square as possible. The final number of segments, n1*n2, might be slightly different from N (so if greater control is required, use n1 and n2).

.For important advice on subdividing please look at section 3.4 of the Users Guide or the general advice on segmentation.