[FLASH-USERS] [Hydro]: Computed dt is not positive! Aborting!

[Ryan Farber]

Hi J.Z.,

In general, dt becomes very small because either
1) bulk speed becomes very large
2) sound speed becomes very large
3) alfven speed becomes very large

Since you mentioned Biermann battery, I would guess the magnetic field
becomes too strong. You can check which is the culprit either by computing
the speeds from an output file using for example yt:
https://yt-project.org/ Or,
you can check the *.dat file.

Best,
--------
Ryan


On Sun, Aug 18, 2019 at 7:26 PM 王荐钊 <astrowjz at mail.bnu.edu.cn> wrote:

> Hello FLASH USERS !
>
> When I add Biermann Battery module to my simulation like this, after
> running many steps, I will get an error message “[Hydro]: Computed dt is
> not positive! Aborting!” I think it is related to documents
> “Hydro_computeDt.F90” and “hy_uhd_dataReconstOneStep.F90”, but I don’t know
> how to fix it. So any advice?
>
> Thanks,
> J.Z. Wang
>
>
> [ERRORS]:
>
>
>
>
>
> ————————————————————
>
> Jianzhao Wang
>
> Department of Astronomy, Beijing Normal University
> No.19, Xinjiekouwai Street, Haidian District, Beijing, 100875
>
> Tel: +86 13141149966
> Email:astrowjz at mail.bnu.edu.cn <astrowjz at mail.bnu.edu.cn>
>           astrowjz at 163.com
>
>
>
>
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