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-   -   hot-spots and cold areas where they shouldn't be (https://www.cfd-online.com/Forums/phoenics/102146-hot-spots-cold-areas-where-they-shouldnt.html)

miriam@efg May 23, 2012 09:47

hot-spots and cold areas where they shouldn't be
 
Hi there,

I'm trying to simulate the temperature equalisation of a high rack storage area.
The circulating air between the rows and pallets is realized with angled-inlets and angled-outlets.
The medium is air using ideal gas law with an inflowing temperature of -25 °C. The Outside Temperature is 34°C and the walls are of medium concrete (or fibre glass) with specific heat transfer.
The mesh is automatically set and Turbulence Model is KEMODL.

So why do I get temperature areas with temperatures over 230 °C and also areas with temperatures under -120 °C with the center in the middle of nowhere. This is totally not working even when I do 800 Iterations and the concergence lines look totally horzontal (it even got worse).

please help...Thanks

Andrew88 June 14, 2012 05:58

Hi Miriam,

Where are these odd temperatures appearing? are they cells in the main bulk of the air or do they appear as trapped cells "inside" a solid object? if you let your model run for a few sweeps (3 or 4 is fine) you can then stop it and check the variable PRSP. This shows how well PARSOL is working to represent your solid objects (set the solid objects to wireframe to see it better).

If you do have a cell full of air inside the solid, this could be the problem. A solution could be to reduce the mesh size in that area, or under the PARSOL settings, set the limits to 0,05 and 0.95, so that it ignores anything smaller than that.

A


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