[CC] Cylindrical coordinate system convention: name of the axes

Hello,

This issue mainly aims at removing the ambiguity of calling "tangential component" the component along the second axis in the cylindrical coordinate system. In fact there is no ambiguity in 2D because there is only one tangent to radial direction, so the tangential direction is necessarily the one which is perpendicular to radial direction. However in 3D, the "tangential" term refers to a plane defined by its normal, and so in this case this plane contains an infinity of tangential directions.

Besides, it is the opportunity to freeze the name of all directions as a convention so we only use one term in every script and plot legend. Here are the main different terms I found in the litterature:

for the first axis: radial direction (I think this one gets everyone to agree).
for the second axis: circumferential direction / azimuthal direction
for the third axis: axial direction / longitudinal direction

On my side I'd rather use "circumferential" and "axial", because "azimuthal" makes more sense to me in spherical coordinates, and axial is clearer and shorter than "longitudinal".

What do you think about this naming convention ?

Once we agree on a convention, we can perform the renaming inside a Pyleecan branch.

Best regards, Emile

Eomys / pyleecan

[CC] Cylindrical coordinate system convention: name of the axes #176