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Messages - Aeolus

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1
PyroSim / No smoke in second exported video (Pyrosim Results 2018)
« on: December 20, 2018, 06:26:25 am »
Dear all,

Symptoms:
--------------
I set 'show' for the '3D smoke' and I choose a nice view. Using F10 I export a movie; everything goes fine; the movie is perfect.
I change the view (and only the view), and I use F10 to export the same video but from a different view.
This time the video is still exported and written to my hard-disk, but there is no smoke in the video.... (the video still shows e;g. changes related to activation/deactivation of geometry elements, so the video is not simply a still shot of the initial state; everything seems OK, except for the 3D smoke)

If now I export snapshots using F11, the same happens: snapshots are written, but without any smoke on them; while smoke is very well visible on the screen.
When I record the screen to produce a movie, the smoke is visible as it should be.

This is not the case with 2D slices; these are always correctly rendered to the video. It only happens with 3D smoke.


Work-around:
-------------
For me it works to reread the results (refreshing results is no enough) prior to exporting the second video. But with a bit of luck this strange behavior can be solved in a future version...
Has anyone else experienced the same issue?
I did not test whether this is related to the movie file format or the settings for the movie export.

best regards,
Joeri

2
.:. 20/XII/2018
I'm using the latest version of Pyrosim.

Symptoms:
--when a simulation case is opened in Results for post-processing, after closing and reopening the case, the viewpoints I created are no longer there.
--Importing viewpoints from a _resultsviews.json file returns an error.

After some investigations of the files, I found that this is related to the settings regarding local language. On a Windows machine here typically the local language settings (Dutch) are a comma ',' as a decimal separator instead of the dot '.'.
Results writes viewpoints to the .view file using this local setting for the decimal separator.
But this screws up the file format...   
When results reads/imports a .views-file, it assumes a '.' as decimal separator.

So what Results writes on my machine:
...
   {
      "camera_type" : 0,
      "name" : "vanbezijden_5proc",
      "nav_tool" : 2,
      "state" : {
         "fov" : 210,7634582519531,
         "loc" : [ 101,6530075073242, -102,8056793212891, 4,040990829467773 ],
         "ref" : [ 99,97814941406250, 7,578149795532227, 3,178250074386597 ],
         "up" : [ -0,04989999905228615, 0,0000000000000000, 0,9987999796867371 ],
         "zoom" : 1,791442275047302,
         "zoomloc" : [ -0,01291329693049192, -0,03672822937369347 ]
      },
      "type" : "camera_view",
      "version" : 1
   }
...

And what Results wants to read:
...
   {
      "camera_type" : 0,
      "name" : "vanbezijden_05proc",
      "nav_tool" : 2,
      "state" : {
         "fov" : 210.7634582519531,
         "loc" : [ 101.6530075073242, -102.8056793212891, 4.040990829467773 ],
         "ref" : [ 99.97814941406250, 7.578149795532227, 3.178250074386597 ],
         "up" : [ -0.0499, 0.0, 0.9988 ],
         "zoom" : 1.791442275047302,
         "zoomloc" : [ -0.01291329693049192, -0.03672822937369347 ]
      },
      "type" : "camera_view",
      "version" : 1
   },
...


Found work-around:
-------------------------
The work-around for me is to maintain a separate _resultsviews.json file with the correctly formatted numbers and import from that file the views; each time when I close the case, Results writes out in the wrong format; after every reloading I need to re-import the viewpoints. Not a huge problem now I found this work-around, but maybe Thunderhead Engineering can solve this issue in a future version...


best regards,
Joeri

3
PyroSim / Direction of internal fans changed when FDS5 --> FDS6
« on: January 06, 2014, 12:24:32 pm »
Dear all,

I often use internal fans in car park smoke exhaust simulations. I had a case that caused me quite some troubles in FDS5 due to repeated numerical instabilities. In FDS6 however the simulations remain stable, so that's a good step forward!

But I had a minor problem when making the switch: all the internal fans changed flow direction: they all started to blow backwards.

To investigate the problem, I started a pyrosim 2012 session and a pyrosim 2013 session; in both I imported the FDS5 fan_test sample file that comes with both installations. I ran both models and indeed: fan directions are switched!

Anyone out there who encountered the same?
Is there an easy to understand reason why this happens?

I switched velocity value signs on my car park fans, and launched the simulation again.  I hope to got the same results as in the Pyrosim 2012 model...

happy modeling,
cheers,
Joeri

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