Hello all, > Could you give more details about the physics you are trying to add? > "atmosphere" in this context usually means an artificial low density > fluid in a matter simulation which helps with numerical problems that > occur when the density drops to zero. It doesn't make sense to add > it to a BBH simulation, which is vacuum. > > Do you mean that you want to add a low density fluid to a BBH > simulation? In case you are planning something similar to https://arxiv.org/abs/1704.07383 then you may want to contact the first author (Joseph Fedrow) possibly through this list (he's subscribed). Typically you will get failures of con2prim near the punctures and have to take special measures to work around it.
Usually this involves setting * GRHydro::recon_method = ppm # since it is very robust * GRHydro::reconstruct_Wv = yes # avoids some v^2>c^2 situations * GRHydro::riemann_solver = "Marquina" # better than HLLE for this * GRHydro::sqrtdet_thr = 10. # or so, these apply Joshua Faber's methods described in https://arxiv.org/abs/0708.2436 * GRhydro::c2p_resort_to_bisection = yes # try bisection if Newton-Raphson iteration fails Note that my recollection of the paper by Fedrow (I am a co-author) was that all of those were required but not quite enough and that Christian Ott had to write a special con2prim routine that handled the BH interior carefully. There is a also code in TwoPunctures that can solve the constraints (the TP code is in the ET but not the code that eg provides a density profile). Again best would be to contact the authors (all reachable through this list). Yours, Roland -- My email is as private as my paper mail. I therefore support encrypting and signing email messages. Get my PGP key from http://pgp.mit.edu .
pgpCmpskiDz6A.pgp
Description: OpenPGP digital signature
_______________________________________________ Users mailing list Users@einsteintoolkit.org http://lists.einsteintoolkit.org/mailman/listinfo/users
