Butterfly output inconsistencies

Hello everyone,

I have been using the following outdoor airflow definition to run a CFD analysis for my model, but all I am getting is a small area with wind vectors that seem to be following the previous sample geometry that was embedded in the .gh file. I inspected all of the components, but none of my changes seem to register and the program runs for 40 iterations or show to yield this:

How can I expand the area to cover the whole geometry? Also, in case you know CFD conventions, is the box size I defined proper?

I am attaching the definition and the .3dm geometry. Look at step 3. to run the simulation.

Thank you for your time guys, I will keep looking for a solution on my end.


1_UTCI.3dm (2.1 MB)
Outdoor_Airflow_Updated_TN.gh (435.0 KB)

Hi @theo_dim,

I have used the ground surface in your model to generate analysis surface. I have highlighted in the attached file where I have made that change.Outdoor_Airflow_Updated_TN.gh (431.3 KB)

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Please setup a profile picture

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Thank you @devang, that did the trick! I now see the wind vectors are pointing in the direction that I set at the prescribed speed. The resolution is not as great from what you can see in the image below:

Meaning the wind seems to not cross between volumes , or treat the urban layout as a single volume in some localized cases. Regarding the color scheme, I investigated the color palette and the ranges to see if I am experiencing similar problems to the previous UTCI definition, but that didn’t seem to recolor the arrows based on their intensity. How would you approach it?

Thank you again for your help so far, it’s been invaluable.
Outdoor_Airflow_Updated_TN.gh (424.0 KB)

Since I am running the advanced version of Butterfly, I am not able to run your file. And in this case, I am not able to figure out why the vectors are not coloured. I will suggest the following;

Outdoor_Airflow_Updated_TN.gh (431.2 KB)

1 I have turned the preview on of the recolor mesh component. Please run the simulation and share with us the picture of the legend. We want to see what kind of wind velocity you are receiving as results.

  1. If the results are not what we would expect then you’ll need to offset the analysis plane from the building. An offset of 0.5 meters would be good enough.