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Author Topic: No reaction occuring in smokeview  (Read 3772 times)

mdangelmaier

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No reaction occuring in smokeview
« on: April 02, 2015, 09:35:27 am »

Hi,

we are currently working on a project using PyroSim.

When I start smokeview no reaction, smoke or temperature is shown hence I guess no reaction is happening.

I defined a fire source using a vent on top of a component and used the polyurethane standard reaction. Do I somehow have
to link the vent to the reaction component?

Thanks for the help.

Max
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Dave McGill

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Re: No reaction occuring in smokeview
« Reply #1 on: April 02, 2015, 09:51:03 am »

Hi,

Can you attach your .psm file?

Dave
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Dave McGill
firemodel.ca

mdangelmaier

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Re: No reaction occuring in smokeview
« Reply #2 on: April 02, 2015, 04:00:48 pm »

Hi,

yes sure, I guess this makes it much more easier :)

Max
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Dave McGill

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Re: No reaction occuring in smokeview
« Reply #3 on: April 02, 2015, 07:13:51 pm »

Hi Max,

There are a number of problems.
1. the cells are an odd size, and the obstructions and vents don't line up with the cell divisions
2. there are no OPEN vents, so it is a sealed box
3. something is wrong with your custom reaction (which I haven't sorted out)

Have a look at test2.psm (attached). It is a fire vent on the floor of the domain. This demonstrates that a burner with the default reaction will work. Before trying to fix your model, I suggest you run couch.fds and room_fire.fds from the fds6 examples folder. Open the .fds files and see how they have been constructed.

What I would do to fix your model is,
1. set your cells to 0.1 m a side, and realign the meshes
2. align the edges of all features to the new cell divisions
3. add OPEN vents to the domain boundaries, where appropriate
4. once you get a fire going in that set-up, go back and trouble-shoot your custom reaction

Dave
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Dave McGill
firemodel.ca

mdangelmaier

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Re: No reaction occuring in smokeview
« Reply #4 on: April 03, 2015, 10:43:07 am »

Hi,

thanks for the answers, I'll try to apply your suggestions to my model.

Unfortunately I can't open your .psm file because I use an older version of PyroSim (2014.2.0807)

Max
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Dave McGill

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Re: No reaction occuring in smokeview
« Reply #5 on: April 03, 2015, 10:49:23 am »

I just wanted to test the burner, so I took out everything, put a burner vent on the bottom of the domain, and changed to polyurethane as a reaction.
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Dave McGill
firemodel.ca

mdangelmaier

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Re: No reaction occuring in smokeview
« Reply #6 on: April 03, 2015, 11:01:05 am »

Okay so I just took your advice and tested the room_fire from the fds6 example folder. I ran the simulation for about 20s (200 time steps) and
somehow I have the same problem that I neither smoke nor any change in temperature occurs. Might there be a problem with smokeview? I use
smokeview 6.1.11

Max
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Dave McGill

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Re: No reaction occuring in smokeview
« Reply #7 on: April 03, 2015, 12:29:49 pm »

Patience Young Grasshopper  :-)

Let room_fire run to completion. I've attached the input files for both room_fire.fds and couch.fds. I've added comments which should help you understand how each is set up.

For your own model, I suggest you start with,
- a fire vent on the floor of an empty domain with OPEN vents; if that works then
- move the fire onto an obstruction; if that works then,
- add the rest of the obstructions.

Dave
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Dave McGill
firemodel.ca

mdangelmaier

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Re: No reaction occuring in smokeview
« Reply #8 on: April 04, 2015, 09:23:26 am »

Okay, so now it works. I patiently followed your steps and it turned out that the ceiling in my model seems to be the problem. When I disable the ceiling
the simulation works fine.

Thank you very much for the help Dave!

Max
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Dave McGill

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Re: No reaction occuring in smokeview
« Reply #9 on: April 04, 2015, 09:42:38 am »

You're welcome.

I thought the problem was the mis-match between the dimensions as specified in the model, and the grid. Smokeview will build everything according to the grid dimensions, which is why I encourage the use of nice even cells, such as 0.1 m a side, and all dimensions in the model being divisible by 0.1 m.

Dave

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Dave McGill
firemodel.ca