Urban size simulation with high values result and no visualization

[Pompey]

Hi guys .
I have a problem when I tried to use butterfly to simulata a urban size model .
I found some similar issues in both iscourse and github , and the possible solvations I know now are two following operations:

1.Refind and smooththe mesh for the reason that it requires a high quality mesh to calculate .
2. Offset the calculation surface , because some probes may cosidered as inside the building .
I tried both , however , I still got unusal values as you can see in the illustrate.

The mesh I created :

The test point I created :

無題2.3dm (29.3 KB)
urban size CFD simulation.gh (450.8 KB)

I really need you help ,I have tried several way but it just doesn’t work .
Please tell me if you have any possible solvations or ideas ! ! Thanks ! !

[devang]

Please try refinement levels (1,1) at Butterfly_Create Butterfly. Remove refinement region.

[Pompey]

Thank you devang ! I will try you suggestion and tell you the result later.
But I am little confuse about the different between refinement levels and cell size , are they having the same impact on create grids for calculation ?

[devang]

Please check the image in this post.
So if your cell size is 1m;

1. At Level 1, the minimum cell size will be 1 meters
2. At level 2, the minimum cell size will be 0.5 and so on so forth.

[jakob]

@Pompey & @devang - did this issue get resolved? I think I’m having a similar issue and would love to know how you solved it? this is what is looks like for me:

[Pompey]

Hi jakob, just saw your reply, not sure whether my solution work for you or not:

1. First, make sure all probes are outside the building solid, you can check this by checking the values of wind speed, if there are some values are qiute huge than other values, which means those corresponding probes are inside the solid. usually offset the boundary curves of solid with 1m and cut the test mesh.
   2.Follow @devang 's suggestion, set refinement levels(1,1).