Hello everyone,
I am studying how to use Einstein_toolkit, I want to try to add atmosphere to a BBH evolution. I add the below things to BBHLowRes.par in the par dir. However, it reports "nan" error soon after the beginning of evolution. I do not know how to correct it. Could anyone give me some suggestion?
" ActiveThorns = "GRHydro" ActiveThorns = "GRHydro_InitData" ActiveThorns = "HydroBase" ActiveThorns = "EOS_Omni"
HydroBase::initial_hydro = "only_atmo" HydroBase::evolution_method = "GRHydro" HydroBase::timelevels = 3
SpaceMask::use_mask = "yes" GRHydro::GRHydro_countmax = 100 GRHydro::riemann_solver = "HLLE" # Marquina is currently not supported by MP GRHydro::recon_method = "ppm" GRHydro::GRHydro_stencil = 3 GRHydro::bound = "flat" GRHydro::rho_abs_min = 1.0e-6 GRHydro::GRHydro_atmo_tolerance = 0. GRHydro::c2p_reset_pressure = "yes" GRHydro::GRHydro_eos_type = "General" GRHydro::GRHydro_eos_table = "Ideal_Fluid" GRHydro::GRHydro_MaxNumSandRVars = 0
GRHydro::use_enhanced_ppm = "yes" GRHydro::sync_conserved_only = "yes" GRHydro::reconstruct_Wv = "yes" GRHydro::c2p_resort_to_bisection = "yes" GRHydro::use_cxx_code = "yes"
TmunuBase::stress_energy_storage = "yes" TmunuBase::stress_energy_at_RHS = "yes" TmunuBase::timelevels = 1 TmunuBase::prolongation_type = "none" TmunuBase::support_old_CalcTmunu_mechanism = "no"
EOS_Omni::gl_gamma = 2 EOS_Omni::gl_k=100 EOS_Omni::poly_k = 100 " Yours, Zhi-Chao, Zhao Institute of High Energy Physics, CAS, China.
On 17 Aug 2017, at 09:57, 赵志超 yanyuechuixue@gmail.com wrote:
Hello everyone,
I am studying how to use Einstein_toolkit, I want to try to add atmosphere to a BBH evolution. I add the below things to BBHLowRes.par in the par dir. However, it reports "nan" error soon after the beginning of evolution. I do not know how to correct it. Could anyone give me some suggestion?
Hi,
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?
Thank you Ian Hinder.
Yes I want to add a low density fluid to a BBH simulation.
I review the source code of GRHydro_InitialData Thorn's GRHydro_OnlyAtmo.F90 . I found it give any position ( I mean every nx,ny,nz) a rho value which is a constant equal to "rho_abs_min" or "initial_rho_abs_min".
so I think it can give a low density fluid to a BBH simulation.
But it report "NAN" or "Con2Prim: count > GRHydro_countmax".
Thank again.
Yours Zhi-Chao.
2017-08-18 21:54 GMT+08:00 Ian Hinder ian.hinder@aei.mpg.de:
On 17 Aug 2017, at 09:57, 赵志超 yanyuechuixue@gmail.com wrote:
Hello everyone,
I am studying how to use Einstein_toolkit, I want to try to add atmosphere to a BBH evolution. I add the below things to BBHLowRes.par in the par dir. However, it reports "nan" error soon after the beginning of evolution. I do not know how to correct it. Could anyone give me some suggestion?
Hi,
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?
-- Ian Hinder http://members.aei.mpg.de/ianhin
On 18 Aug 2017, at 10:05, 赵志超 yanyuechuixue@gmail.com wrote:
Thank you Ian Hinder.
Yes I want to add a low density fluid to a BBH simulation.
I review the source code of GRHydro_InitialData Thorn's GRHydro_OnlyAtmo.F90 . I found it give any position ( I mean every nx,ny,nz) a rho value which is a constant equal to "rho_abs_min" or "initial_rho_abs_min".
so I think it can give a low density fluid to a BBH simulation.
But it report "NAN" or "Con2Prim: count > GRHydro_countmax".
OK, thanks for the clarification!
I'm not an expert on GRHydro, but maybe someone else can suggest something?
Are you planning to solve the constraints?
Thank you Ian Hinder.
At the first step, I just want to add a low density fluid to the BBH simulation (mimic the atmosphere around the BH) to see how it evolution (I remember I had read a paper which describe this kind simulation, and I want to repeat it.). I put the fluid static in the initial data.
I think I will give some constraints on the fluid static in the initial data in the future. Maybe it need to write a new thorn, I think.
Yours, Zhi-Chao.
2017-08-18 22:43 GMT+08:00 Ian Hinder ian.hinder@aei.mpg.de:
On 18 Aug 2017, at 10:05, 赵志超 yanyuechuixue@gmail.com wrote:
Thank you Ian Hinder.
Yes I want to add a low density fluid to a BBH simulation.
I review the source code of GRHydro_InitialData Thorn's GRHydro_OnlyAtmo.F90 . I found it give any position ( I mean every nx,ny,nz) a rho value which is a constant equal to "rho_abs_min" or "initial_rho_abs_min".
so I think it can give a low density fluid to a BBH simulation.
But it report "NAN" or "Con2Prim: count > GRHydro_countmax".
OK, thanks for the clarification!
I'm not an expert on GRHydro, but maybe someone else can suggest something?
Are you planning to solve the constraints?
-- Ian Hinder http://members.aei.mpg.de/ianhin
Sorry lan Hinder,
I miss-understood your words "constraints". I thought you are asking me whether I give the initial data some initial velocity so that it can surround the BH stably (if there is only one BH).
Now I know your meaning, and I am trying to solve them.
Thank you.
Yours,
Zhi-Chao.
2017-08-18 22:55 GMT+08:00 赵志超 yanyuechuixue@gmail.com:
Thank you Ian Hinder.
At the first step, I just want to add a low density fluid to the BBH simulation (mimic the atmosphere around the BH) to see how it evolution (I remember I had read a paper which describe this kind simulation, and I want to repeat it.). I put the fluid static in the initial data.
I think I will give some constraints on the fluid static in the initial data in the future. Maybe it need to write a new thorn, I think.
Yours, Zhi-Chao.
2017-08-18 22:43 GMT+08:00 Ian Hinder ian.hinder@aei.mpg.de:
On 18 Aug 2017, at 10:05, 赵志超 yanyuechuixue@gmail.com wrote:
Thank you Ian Hinder.
Yes I want to add a low density fluid to a BBH simulation.
I review the source code of GRHydro_InitialData Thorn's GRHydro_OnlyAtmo.F90 . I found it give any position ( I mean every nx,ny,nz) a rho value which is a constant equal to "rho_abs_min" or "initial_rho_abs_min".
so I think it can give a low density fluid to a BBH simulation.
But it report "NAN" or "Con2Prim: count > GRHydro_countmax".
OK, thanks for the clarification!
I'm not an expert on GRHydro, but maybe someone else can suggest something?
Are you planning to solve the constraints?
-- Ian Hinder http://members.aei.mpg.de/ianhin
-- 赵志超 中国科学院高能物理研究所 中国 北京 18401696963 yanyuechuixue@gmail.com
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
Thank you Roland,
https://arxiv.org/abs/1704.07383 is exactly what I want to repeat.
Thank you for you help, I will contact the 1st author for help of your paper if I failed.
Best Wishes.
Yours, Zhi-Chao.
2017-08-18 23:44 GMT+08:00 Roland Haas roland.haas@physics.gatech.edu:
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 .
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