Hello,
I am trying to develop a local cylindrical coordinate system in a helix geometry where the longitudinal z direction is along the path of the helix, the radial direction r extends radially outward from the center of the helix's minor radius and phi is orthogonal to both. I used the Curvilinear Coordinates Adaptive Method on a helix to obtain a local cartesian coordinate system and used those results in the built-in Cylindrical System defined in the definitions. The cylindrical system appears have problems with the the helix basis vector inputs for the longitudinal and phi directions. I previously implemented the same idea of using the Adaptive Method results in the Cylindrical System on a cylindrical geometry with good results, however, there seems to be a problem with curved basis vectors. Would anyone know how to implement a local cylindrical system, preferably using the Cylindrical System. I am using COMSOL 5.4.