COMSOL v5.x has possibility to use an Adaptive method in order to define Curvilinear coordinates system (https://www.comsol.com/blogs/defining-curvilinear-coordinates-anisotropic-materials/). According to description of the method, the adaptive method adapts the computed vector field to maintain a constant streamline density on the cross section.
1) What is mathematical or physical background of the Adaptive method?
2) What are system of equations used to compute vector field in Adaptive method?
3) What are boundary conditions used to compute vector field in Adaptive method?
Thank you in advance,
Algis