Hi,
I am new to Fenics. Right now I am doing a transient heat conduction problem with complex 3D geometry. I generated the mesh using the STL geometry file and Netgen 5.1, then export the mesh in Diffpack format, and use dolfin-convert to convert the mesh for Fenics successfully. It created the mesh xml file with several *_marker_x.xml files (where x is a number started from 1). Also I can use mesh=Mesh("my_mesh.xml") to load in the mesh and plot it.
My problem is that how to define the boundaries? In my case, most of the boundary surfaces have adiabatic condition (dT/dn=0) except two surfaces: on one of them the temperature is given, on another one the heat flux (k*dT/dn) is given.
In the FEniCS tutorial document, all examples have relatively simple geometry, and the boundaries are defined using the conditions of the boundary coordinates. This won't work for my case.
Could you please share or point to an example with a complex 3D mesh generated by an external mesher which can illustrate how the boundaries are defined in FEniCS python code?
Thanks,
Yong Chang
