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?