Reply To: Coordinate system at each point of a surface

[peteroznewman]

Each shell element has an element coordinate system where the s and t vectors are in the plane of the element and the r vector is normal to the element surface. Here is a figure from the Theory Manual.
If you have a solid mesh for the thermal analysis, Workbench makes it very easy to skin the surface of the solid with shell elements. These will each have their own local normal to the irregular surface.