[FLASH-USERS] Units of measurement Sedov sample problem

[Marissa Adams]

Hi Isabella,

FLASH uses CGS.
Pressure ~ dynes/cm^2, Energy ~ ergs
However in the Sedov problem, regarding the normalization, I think the
ExpEnergy is actually an energy density/pressure provided by the shock. I'm
not completely sure You'll want to check if energy is conserved when
visualizing and what is given in the .dat file for the total energy (for
reflecting BC). From doing that you'll be able to determine the factor (if
it's mass or volume).

You can also tell what units are being used by opening the (e.g. sedov).log
file for the problem you've run and search for "unit":

You'll probably find:

   - a list of the known units of measurement
   - along with physical constants used
   - you can also check while searching in the file and verify:

   pc_unitsbase                = CGS

Hope this is helpful,
Marissa

---
Marissa Adams
PhD Student
Website: http://www.pas.rochester.edu/~madams
University of Rochester
Department of Physics & Astronomy
371 Bausch & Lomb Hall


On Tue, Jun 19, 2018 at 8:15 PM Isabella M Pagano <ipagano at utexas.edu>
wrote:

> Hello,
>
> I've looked over the user manual several times and it doesn't specify what
> units of measurement the different parameters are in. I've just been
> running the Sedov equation sample problem, and was wondering what it was
> normalized to/what units because it isn't actually explicitly mentioned. I
> can deduce that the pressure is in bar because the unit given is 10^-5
> which is equal to one pascal, so I'm assuming that it is in bars. However,
> the default density/energy are 1, so what is that supposed to be normalized
> to? Is there a convention I'm not aware of in this instance?
>
> Thanks!
> Bella
>
>
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