[ff3d-users] Basic Question on Fictitious Domain method

[Juzar Thingna]

Hello Everyone,
I'm quite new to the fictitious domain method of solving PDE. I wanted to know how is this method better than the Finite element method? while doing some basic research one advantage I see is that the number of iterations for convergence in CG is quite small in complex geometries because of the pre-conditioner used. But I'm still not able to figure out how the geometry can make the matrix ill-conditioned? 

Any help or basic reading would be really helpful.

Regards,  
Juzar Thingna
Center for Computation Science and Engineering
National University of Singapore