d 'outletBoundary' components in which the 'temperatures_' represents?
The 2nd ques is more about thinking how to achieve more potentials by BF. I am doing a project that is trying to implement the construction method of 'DOUBLE-GLAZED' facade, which will conduct air flow inside a building and save more energy. Since I also use LB&HB for time-based analyses, so I`m wondering if BF could use time-based-srf-temperature to achieve a more dynamic simulation in a day, let`s say, a hot summer day, 10:00 to 16:00?
And the last what is the definition of these recipes(pic no.2)? what do they mean?
Thanks in advance for the helps!
Best wishes,
Lei…
see, the results indicated in the error for pressure are, well I don't think I know the name for those numbers. But values of XE+118 mean the simulation was diverging. I would recommend you to update BF, if you haven't already, re-run the case and test after.
Also, you can post your mesh settings here. Most other times is mesh quality causing this.
Kind regards,
Theodore.…
he potential of BF to assess such cases. In your search, try and be specific on what you want, cause validation can focus on codes (i.e software environments like OF and Fluent), solvers (e.g. RNG vs kEpsilon vs kOmega, etc.), meshers, and so many more. Additionally, I'm sure there's a lot of CFD studies of Atrium spaces.
Myself, I haven't been involved in any validation studies as I have always used CFD on the practical side of things. Therefore, I always trusted OF since it has been heavily validated over the years.
The beauty of BF, or at least its end goal, is that you can easily test design alternatives directly from a friendlier and possibly better-known environment of Rhino3D.
I would suggest therefore to just try things out. Design your geometry, in this case the atrium, in Rhino. Decide which are the parameters that you wish to investigate and incorporate those to a GH definition that produces different design alternatives for the range of those parameters (i.e. your parametric model). Then run the cases through BF. There's a couple of examples that come with BF and a few others users are providing either here or on github.
I'm afraid trial and error is painful with CFD but it's the best way forward. Also, I suggest you bookmark cfd-online.com and skim through everything in there. Most if not all of what we are discussing has been discussed there.
Good luck!
Kind regards,
Theodore.
…
amp; n2 != null)
{ //...blahblahblah
}
Also, the CastTo and CastFrom functions are pretty low level. It's easier to use the conversion methods in Grasshopper.Kernel.GH_Convert.
--
David Rutten
david@mcneel.com
Leusden, Holland…
Added by David Rutten at 5:40am on August 29, 2011
, a1200)}) Is there any way I can make this list into {a1, a2, a3, a4, -a5, -a6, -a7, -a8, a9, a10, a11, a12, -a13, ..... , a1200} ? ( 4 positive signs then 4 negative signs and so on) - alternating every nth in general.
or
2. Is there any way (workaround) to get negative angle value from 2 vectors? I know 'ANGLE (of 2 vectors)' component by itself doesn't work and I know why too. I have feeling that the reflex angle output might be useful but again, matter of list manipulation.
Any help would be greatly appreciated. Thanks in advance.
Hyo
…
ossibly not doable atm. However, I think it would be quite inefficient way to run things.
My above answer was concerning this sentence
Or can I even set up a case on my Windows Laptop and use the seperate Linux machine (or maybe even an Amazon EC2 instance) to run the OF calculations?
This is certainly possible with the use of BF I described above. Concerning AWS instances, I am about to find out this week hopefully when I'm going to try my first cloud OF run. Will let everyone know if I do.
Kind regards,
Theodore.…
nts but as there are polylines and surfaces in it, they are conflicting as the geometries are overlapping and intersecting.
The input for the model is a centre point and four connecting points: we can call them CNT, A, B, C and D. The model works for these points - it's quite complicated with lots of polylines, vector geometry, surfaces, rotations, etc. - but it still works and has an output of two breps.
If I had a compilation of N sets of CNT, A, B, C and D's, is there a way of feeding each of these into the grasshopper in individual sets rather than just plugging in the huge set of numbers - e.g. feeding in CNT1, A1, B1, C1 and D1 and getting a result before moving on to CNT2, A2, B2, C2 and D2?
I've tried looking through tree structures, but it seems to be failing when the size of the set isn't known - e.g. how to extract all the information from trees when N isn't know using list item (i=0, i=1, i=2..., i=N).
I hope I've managed to explain the problem adequately, I can make up an easier to understand Grasshopper model later if I haven't explained well...
Thanks in advance for any comments, pointers, etc.…
It seems that the X and Z direction are graded, with the grading in the X direction not being symmetrical (which is ok if X is the wind direction). If you didn't we would need to check our default settings but if memory serves they should be set at no grading.
As a side note here, a suggestion is to keep your refinement levels, either global or the ones set per boundary, to equal (optimal case) or not very different values. The (2,10) you supplied could potentially create sudden cell size changes which is not optimal, even though probably the 10 isn't going to be used. Settings like (2,3) or (2,4) would be ok. If you want to go higher, raise both numbers.
The update fvSchemes functionality is an added option of BF itself and not a command within OF. Essentially what it does is apply proper schemes to your model according to the mesh quality you have achieved. This is why OF won't recognize it. When we get BF going with the new version this will be done automatically for you.
Finally, the error you are seeing is again eliminated through the use of BF which takes care of the clean up and folder set up for you prior to running the case. For now, to do it manually, what you need to do is this:
1.Delete the /constant/polyMesh folder
2.Cut the polyMesh folder from the /2 folder and paste it to your /constant/polyMesh folder.
3.Delete the /1 and 2/ folders
4.Rename the /0.org folder to /0 (if that was not the case already)
4a.Run the case in serial mode with the simpleFoam command.
or
4b.Run the case in parallel with:
decomposePar mpirun -np x simpleFoam -parallel
Where the x is the number of processors set in your decomposeParDict found in the /system folder, usually set at 4. You can change that number of processors by simply changing that number in the beginning of the dictionary. To avoid other problems here with different number of processors change to scotch method in the same dictionary.
P.S.: Another easier but dirty (to my sensibilities) way is to simply paste the 0 folder inside the 2 folder. Provided boundaries and boundary conditions are set ok this should run. This would work for the serial way.
I hope this helps! When BF is up and running soon most of this will be hidden in the background. But the brute force method you are taking now is also quite educational.
Let me know if you have any other questions or issues! Thanks for testing!
Kind regards,
Theodore.
…
ntended for an easier application of BF and not really for learning how to use BF, hope it was helpful. Not sure what this error is though as I can't reproduce it in my computer. Are you sure you have the latest Human components? I'll try and look it up when I can for you.
Concerning your results, they do look as expected. A heavy wake area behind the building has been created as you can see, with a quite clear pattern of wind deceleration and a recirculating vortex. This is a standard pattern in outdoor wind and something that generally we try to either minimize or plan activities around since these areas tend to have lower wind velocities and less recirculation, thus leading to debris/dust deposition and potentially higher pollutant concentration.
There are a lot of nice examples of urban wind patterns online you can check, it makes easier for you to help validate the results you get.
Finally, the k and epsilon values for outdoor studies are currently being calculated with (pretty) standard equations for the k-e family of turbulence models. I believe you can find these in the BF source code. Unfortunately I don't have access right now to check where exactly but I would look before the blockMesh component, since the case folder with all the values is created at that point.
Good luck in your CFD journey! Please keep posting results and issues!
P.S.: Btw if you are interested on the effect of your building geometry at a section parallel to the wind direction you could also try a 2D simulation. You can do that either by manually editing your blockMeshDict and setting 1 cell width on the direction perpendicular to your wind or by simply assigning a 1m wide windTunnel (centered at your geometry). This will allow you to refine your model much more than possible in a 3D case with lower run times as well. Ofc it's not as accurate as a 2D case but it's nice for experimentation.
Kind regards,
Theodore.…