multi storey buidling model _Wind volume can't be recognised

[allger]

Hello everyone!!

I created a model of a buiding but simulation cfd can't recognise the the volume between the model bounds and the building.

I get a message that the 2-d model is not planar but as i ve seen in other examples simulation cfd can recognise surfaces that are not planar.

I haven''t assigned materials or boundary conditions to any surface yet in case i should make some changes to the geometry first. I hope someone can check the modle that I attached.Thanks in advance.

[allger]

Ok i should have used a .sat file.

[Jon.Wilde]

It is because CFD works with volumes/solids in 3D. There are only surfaces here and no solid parts. 

Make them solid and this should be fine.

Thanks,

Jon

[allger]

Dear John,

Thanks again for your reply to this and the other posts as well. I used loft (solid as you said ) and then exported to a sat file and it actually worked. here is  the final model that i would like to know your opininion about.

It is very interesting that i get a substantial force transverse to the wind directrion but is it correct?

[Jon.Wilde · Accepted solution]

There are a few things to try to be sure.

Refine the mesh and see if it effects the result, we want to be mesh independent. I tend to refine to 0.7 and see if the results change by more than 5%.

Consider enlarging the domain width - right now you are probably artificially accellerating the flow around the sides of the building

Why are you running compressible? I would think this could significantly throw the results, I would stick to incompressible, your flow rates are only 40m/s

Hope that helps!

Thanks,

Jon