[FLASH-USERS] Total energy and Laser Deposition

[Scott Feister]

Nitish,

To add another possibility to Sijoy's, please look in the latest FLASH4
user manual and ensure you are interpreting the "depo" variable correctly
-- the laser package does not always use the same units as the rest of the
simulation.

Scott

On Sat, Mar 9, 2019 at 10:14 PM Sijoy C D <cjoycd at gmail.com> wrote:

> Hi,
>
> If your computational domain is set with free outflow conditions the
> materials leave the domain carrying internal energy and kinetic energy
> (outflow BC). In the laser slab problem setup, it might be possible the
> background material and at later stages the targets material may flow out
> the computational domain.
> This is only one possibility .
>
> On Sun, Mar 10, 2019, 10:38 AM Acharya, Nitish <nachary2 at ur.rochester.edu>
> wrote:
>
>> Thanks Klaus.
>>
>>
>> Yes, indeed the "energies" in both of the sources have units of energy.
>> Thanks so much for clarifying about it. Right now, I'm having an
>> issue regarding laser energy deposition. How does it compare to total
>> energy? From what I understand, any increase in total energy at any
>> instant should equal total energy deposition until that time. However, I am
>> getting Laser Energy Deposition higher than the total energy at almost all
>> the time instants. Do you have any idea what's going on?
>>
>>
>> Thanks,
>>
>> Nitish
>>
>>
>> ------------------------------
>> *From:* Klaus Weide <klaus at flash.uchicago.edu>
>> *Sent:* Tuesday, March 5, 2019 6:23:05 PM
>> *To:* Acharya, Nitish
>> *Cc:* Scott Feister; flash-users at flash.uchicago.edu
>> *Subject:* Re: [FLASH-USERS] Total energy and Laser Deposition
>>
>> On Tue, 5 Mar 2019, Acharya, Nitish wrote:
>>
>> > Thanks Scott. I thought it was ergs/g as the energies in FLASH
>> > calculated seemed to be all specific energies. So, I did multiply the
>> > energies by mass. Also, since it was a 2D domain, multiplication by
>> mass
>> > was infact mass per length. This is what I did. And I was wondering
>> what
>> > length parameter should I use to get the total energy.
>>
>> The integral quantities written to the flash.dat (or similar) file should
>> have totals of *energy* in the appropriate columns, at least in 3D
>> and in lower-D geometries when the "omitted directions" are angles not
>> lengths. So for 2D cylindrical geometry, they are energies (integration
>> over a full 2\pi range of azimuthal angle is implied).
>>
>> The "power" specified for the Laser energy deposition should indeed be
>> a power (energy / time) also in the 2D cylindrical case, at least if
>> ed_laser3Din2D is used (not sure about when ed_laser3Din2D is false).
>> The "energies" in lasslab_LaserEnergyProfile.dat should then indeed
>> have units of energy, not energy per length.
>>
>> You should NOT have to multiply by mass if you compare energies from
>> those two sources (flash.dat and _LaserEnergyProfile.dat files).
>> And I believe you should not have to multiply (or divide) by a length
>> either, under the mentioned conditions.
>>
>> Klaus
>>
>
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