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-   -   BuoyantFoam and hotRoom in 15 (http://www.cfd-online.com/Forums/openfoam-bugs/62301-buoyantfoam-hotroom-15-a.html)

egp November 13, 2008 09:51

The hotRoom tutorial for buoya
 
The hotRoom tutorial for buoyantFoam in 1.5 gives unphysical results. The same tutorial in 1.4.1-dev and 1.4.1 gives results which look correct (i.e., thermal plume emanating from a 600 degree source on the floor). The 1.5 results never generates the plume, and the temperature collapses to values below the boundary values, which is mathematically impossible. This has been reported on the discussion board, but I've not seen follow-up. The pre-processor, setHotRoom, is working and properly sets the floor temperature. I haven't had a chance to debug, but my guess is that there is a bug in the basicThermo model.

niklas November 13, 2008 10:27

I ran the case in 1.5 and it d
 
I ran the case in 1.5 and it does indeed produce some weird results, but it looks like it has already been fixed in the git version 1.5.x

eugene November 13, 2008 10:33

I can confirm what Niklas said
 
I can confirm what Niklas said. We are running the patched version without any problems.

tstovall December 9, 2008 12:23

I've noticed the same problem
 
I've noticed the same problem occurs for the lesBuoyantFoam solver. When will the corrected patch version be available?

mattijs December 9, 2008 12:52

This should be fixed in the 1.
 
This should be fixed in the 1.5.x git version. Both codes use the same included code.

chrisd February 19, 2009 08:59

buoyantFoam / buoyantSimpleFoa
 
buoyantFoam / buoyantSimpleFoam seems to have been broken again
I have tried both a 1.5.x git build and also most recently the 2009-02-02 1.5-dev code.

The hotroom results I have got are the same as described above – no plume emanates and the temperature drops below 300 – Illustrated here at time=400 for the 2009-02-02 1.5-dev code, http://img207.imageshack.us/my.php?i...eenshotdz2.png

mattijs February 19, 2009 12:29

I ran the 1.5.x buoyantFoam ho
 
I ran the 1.5.x buoyantFoam hotRoom tutorial just now and get a nice plume. Temperature drops slightly below 300K (299.932K at t=25s) due to the segregated solving (if I run with timestep 5x smaller I get a smaller error: 299.949K at 25s).

prashant24983 February 19, 2009 13:38

Chris, clip the temperatur
 
Chris,

clip the temperature range on paraFoam, you will be able to see the the plume.

Prashant

chrisd February 21, 2009 15:54

Thanks for the help – co
 
Thanks for the help – could someone please tell me what sort of range of values I should be getting?

With the standard tutorial case of a 600k patch I get a temperature range of 300.15 - 300.38k at t=400. I'm really new to this and was just expecting it to be larger...

http://img149.imageshack.us/my.php?i...reenshot1a.png

mattijs February 24, 2009 07:52

The hotRoom case is just a tut
 
The hotRoom case is just a tutorial. The flow is not well resolved - in vertical directions cell size is 0.5m! As an experiment just by having more cells in the vertical direction max temperature went up to 307K.


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