this is a new multi grid approach for the cylindrical FDTD.
The FDTD domain will be split in two regions in radial direction.
The "inner" region will have half as many disc-lines in alpha direction and therefore allow for a much larger timestep which increases the simulation speed.
Todo:
- currently only a homogeneous disc is allowed in alpha direction
- some extensions have to be tested and prepared for this approach (e.g. pml)
- speed enhancement and more efficient memory usage
- lots and lots of testing...