Hi, This issue is discussed for example in
http://arxiv.org/abs/1003.4681 where a non-constant damping in the gamma driver shift is presented to handle unequal mass binaries. As far as I remember there may also be later papers with further improvements to the method. Cheers, Peter On Tuesday 2016-06-07 01:00, Frank Loeffler wrote: >Date: Tue, 7 Jun 2016 01:00:59 >From: Frank Loeffler <[email protected]> >To: rahul kashyap <[email protected]> >Cc: Einstein Toolkit Users <[email protected]> >Subject: Re: [Users] Resolving two BH > > On Mon, Jun 06, 2016 at 06:50:04PM -0400, rahul kashyap wrote: >> Thanks for the reply. My apologies that I'm not completely familiar many of >> the physical and numerical issues while simulating bbh. I have experience >> in AMR astrophysical simulations. > > No need to apologize. > >> When I do the bbh simulation of ratio around 1, it evolves perfectly fine. >> With higher mass ratio, the smaller BH just becomes bigger and blows up. >> I'm assuming this as a problem of refinement. > > It is not. It looks like what I described earlier: your gauge > conditions, in particular the shift condition, isn't well suited for the > small black hole. Grid points are "falling in", making it appear growing > on the computational grid. You may try to play with the values such that > the small black hole evolves fine (you can try that with a simulation of > only a small black hole of that size), but then you might find that the > large black hole "vanishes from the grid" because grid points there are > pushed out too much. If this is the case, you might need > position-dependent values. > > Frank > > _______________________________________________ Users mailing list [email protected] http://lists.einsteintoolkit.org/mailman/listinfo/users
