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Impact of empty cells

Posted: Wed Apr 29, 2020 11:22 pm
by Erika
Hi everyone,

I need a little clarification about empty cells please.
When digitazing with SPACES, it is recomended to let empty cells around the area. I know that I have to let, on each side, as many empty cells as the height of the highest building.
However, I wonder if those empty cells can have an influence on the results. Indeed, I tested 2 identical areas with a different amount of empty cells and the results in leonardo were not exactly the same (for example on air temperature). The results also change if I put a different soil type in the empty cells.
By the way, what does "empty cells" mean ? Are they real empty cells or just cells without any kind of building, vegetation...but just a soil profile ?

Thank you for your help.

Best regards,


Re: Impact of empty cells

Posted: Thu Apr 30, 2020 7:10 am
by Tim
Hi Erika,

Those empty cells mean that there should be no buildings, trees should be OK. Soil profile should be fitting to the rest of the model area. If you place a building directly at the border, the model thinks that the building goes on forever. If you have not enough open space, the wind flow is pressed around the building in a very hard way which can cause huge turbulence. That is why there should be some open space near the borders. Of course, simulation results can be become more accurate then since the wind flow is not pressing around the buildings. You are able to cut the area of interest (without the open space around) in Leonardo to only visualize that part of the model area results.

Best regards,