Alright. Approximately how long should this take?
You never know until you do 1st one… especially with the new ‘auto’ # of processors…
Likely 1st time through was making the unlayered mesh, second time through was adding the layering…
EDIT: And since I never use enclosures, I missed that those extra runs had to do with double meshing all the buildings that were left in the geometry since ‘keep existing parts’ was checked when you made your enclosure, live and learn 
Ok, I’ll just wait and hope it works…
Hey @NLim8
I took a peek at your project. You’re facing these issues because your enclosure was made with “keep existing parts” on. When this option is enabled, all the solids (buildings) in your geometry will be kept and meshed. This approach is used for conjugate heat transfer and is not necessary for incompressible, external flows. Resulting meshes are quite big and take longer to run.
I copied your project, re-made the enclosure (with “keep existing parts” off) and ran the automatic hex dominant mesher and it does work as it should:
/Ric
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Thanks for your help! The original mesh (with “keep existing parts” on) finished generating after 356 mins. I wouldn’t really want to scrap it, but would that mesh affect the results of the simulation?
Link: SimScale
Since the keep existing parts is on for that mesh, is this why the simulation isn’t working?
Yes, just redo as Ric did, his only used 3.2 core hours in 6 realtime minutes and ~450000 cells were made 
Like I said, I don’t use enclosures so I missed the error Ric found, sorry.
In those 6 hours your mesh took last night, there were 31 million cells created…
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@NLim8: You cannot expect to finish your mesh with such high refinement… (Region, mainly). Look at your log file from meshing:
Edge intersection testing:
Number of edges : 33997919
Number of edges to retest : 27538260
Number of intersected edges : 2410007
This is still run on 16 cores, but you will exhaust the memory anyway…
Stop that meshing, please and do the first, simple one, letting perhaps the surface refinement on buildings.
But you have to observe the meshing log and see if you are not trying to nuke the fly…
Cheers,
Retsam
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Thanks for your help! The mesh has completed generating. I’m not really sure what happened to my simulation, why aren’t I seeing the different colours?
Would I have to redo the simulation, is there something I didn’t add?
Hi @NLim8 !
If there’s something in the result control items for instance or another BC that you missed, you have to redo the simulation, yes!
For the Stream Tracer, have you used the PICK operation to choose where your streamlines start?
Best,
Jousef
Time: 0.0000? It means that the visualization show status before simulation start. Please move to the simulation end (>>|).
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I used the pick operation, but it just seems like there’s too much blue. Also, how would I make it so that the ground has all the different colours, and that the buildings appear shaded in?
From plot you show, it seems that your simulation went awry. Please check:
Convergence plot
Wind flow in X direction (it should not flow higher then stellar winds 
)
Pressure (same: stellar pressures indicates error in simulation setup).
Read everything you can about Urban confort simulation. I will not do the work in your place. Check public projects and documentation of SimScale.
With converged simulation you will be able to proceed to meaningful visualisation.
Cheers,
Retsam
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I’m really sorry for all the questions. I tried running two new simulations, one making the buildings no-slip walls, then another with added forces and moments, but everything is still all blue. What is causing the problem?
Run 1
Run 2
I’m a high school student, I’ve had no prior experience with CFD simulation, and my project is due on Monday Jan. 13. I’ve been working on it all week and have been running into a lot of problems, and I’m starting to get really anxious… Thanks for all your help, I really appreciate it.
Who told you that CFD is easy?
I made a copy of your project:
Example for Pedestrian Wind Study…
Look at SimCity_TET_Mesh simulation. It has a simplistic TET based mesh of your ‘City’ (270 kNodes). The simulation was run (Run 1) and you have an example of results.
Your simulation domain is much too big and (my) TET mesh is too coarse, but you can (and should) mend it.
I did not mess with hour hex mesh, as I said the domain is too big and so called ‘Numerics’ are not adjusted.
Convergence plot is not terrible, but is acceptable:
I suggest you make a duplication of that project (I played with) and try to get something better I did in 15 minutes.
Cheers,
Retsam
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Thank you very much! I will make adjustments to the one you made. My teacher told me that I would have to run some sort of experiment to test pedestrian comfort. If I didn’t use CFD, I would have had to create a full scaled real-life model and my own wind tunnel, and I don’t have those materials. Thanks again, and sorry for any inconveniences I may have caused
Thanks a lot Andrzej for helping our user here!
@NLim8, for pedestrian comfort analyses, let me give you some resources that might help you out for your work:
- PWC Release
- Pedestrian Wind Comfort Assessment
- Pedestrian Wind Comfort Validation
- Pedestrian Wind Comfort Modeling
These should help you out, some of them take a bit of time to understand if you have never done an analysis like that before. In case of doubts, feel free to reach out to us! Happy to help you out!
P.S.: You can tell your teacher that we also help educators along with their students, they simply have to apply for an academic plan right HERE or contact me via mail at jmurad@simscale.com
Jousef
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