Khamsin Virtual Racecar Challenge 2015

[CAEdevice]

@CAEdevice I could not find the error. From the log file, it looks like the simulation ran to completion without any issue. In regards to number of processors, this is based on (a) number of processors available on your machine, and (b) size of the case.

Yes, the simulation was completed: https://dl.dropboxusercontent.com/u/522 ... esults.jpg

I think the problem is related to the generation of the html report after the simulation. In particolar it seems to be something wrong whith the surface projection compuitation. I'll run the analysis once again and I'll copy some screenshots.

EDIT: here is the error message: https://dl.dropboxusercontent.com/u/52296215/Error.jpg

[CAEdevice]

In the meanwhile I have a question about the parts names: how can I assign a name to the inlet/outlet surfaces? Should I "cut" a (thin) solid part?

[cdsavage]

In the meanwhile I have a question about the parts names: how can I assign a name to the inlet/outlet surfaces? Should I "cut" a (thin) solid part?

These should be surfaces, not solids. The remaining bodywork should now also be a surface, rather than a solid, because the inlet and outlet surfaces have been split off. They should be separate parts, or separate bodies within the STL file.

Let me know if you have issues exporting surfaces to STL. Some software packages give a warning when you do this.

[CAEdevice]

In the meanwhile I have a question about the parts names: how can I assign a name to the inlet/outlet surfaces? Should I "cut" a (thin) solid part?

These should be surfaces, not solids. The remaining bodywork should now also be a surface, rather than a solid, because the inlet and outlet surfaces have been split off. They should be separate parts, or separate bodies within the STL file.

Let me know if you have issues exporting surfaces to STL. Some software packages give a warning when you do this.

ok, I'd prefer solids ( the PPT posted by Julien talks about "solids") but passing through SpaceClaim I can do everything with STLs, much better than 2014 with that odd skp format

Here is the structure tree of the file, can it work?

test >>> Assembly name
* wheel-front >>> Component
* wheel-rear >>> Component
* engine-intake(s) >>> Component(s)
* engine-exhaust(s) >>> Component(s)
* cooling-intake(s) >>> Component(s)
* cooling-exhaust(s) >>> Component(s)

Only two wheels (1 front + 1 rear) should be incldued?

[cdsavage]

There's a minor issue I noticed with the December 30th release of the parts.step/skp files - the rear wing volume and bodywork volume overlap slightly. The rear wing volume has the correct dimensions, but the bodywork volume should be adjusted to meet the rear wing volume. We will be releasing a release candidate for the rulebook within the next couple of days, this issue will be fixed for that release. I don't anticipate any other changes to the guide files (other than possibly a change in overall Z positioning, explained below), and the only changes to the rulebook are tweaks to the wording.

I believe there's also a conflict between the rulebook and the guide that Julien has released for One-Click CFD, in that the rulebook specifies Z=0 as being the reference plane, whereas One-Click CFD specifies Z=0 as the ground. We will resolve this by either changing the rulebook or One-Click CFD, but in the mean time, you will need to move your car 45mm upwards before using One-Click CFD so that it is correctly positioned.

[julien.decharentenay]

@CAEdevice I could not find the error. From the log file, it looks like the simulation ran to completion without any issue. In regards to number of processors, this is based on (a) number of processors available on your machine, and (b) size of the case.

Yes, the simulation was completed: https://dl.dropboxusercontent.com/u/522 ... esults.jpg

I think the problem is related to the generation of the html report after the simulation. In particolar it seems to be something wrong whith the surface projection compuitation. I'll run the analysis once again and I'll copy some screenshots.

EDIT: here is the error message: https://dl.dropboxusercontent.com/u/52296215/Error.jpg

The error message helped tremendously. The issue lays with something in ParaView (when run in batch mode pvbatch). The issue is not just with the generation of the html report, but also with on-the-fly solution based mesh refinement. In the picture you sent, the mesh is not refined in the wake of the car as it should be. This is achieved by extracting an iso surface of total pressure gradient during the simulation using pvbatch. So this will result in some difference in results.

I am not sure which version of ParaView you are using. first thing is to ensure that the computer is connected to a network when running pvbatch (at least on my computer). I am having issue with ParaView v4.1 and am still using v3.98. You may want to try these.

As a test, you may want to try the following command from where the openFoam results are located (ie the directory where analysis.foam is located:

Code: Select all

"c:\Program Files (x86)\ParaView 3.98.0\bin\pvbatch.exe" "C:\Program Files (x86)\One-Click FD\Scripts\ParaView\main.py" --render3D -loadOpenFoam=analysis.foam,internalMesh --showAsBlackSurface -p=out.jpg

See if you can reproduce an error message similar to the one you showed, and then try to find a solution. You obviously will need to change the path to pvbatch above (I am assuming main.py) will be in the right place. Keep in mind that I am making you digging a bit deep into one-click CFD/CFD Apps, so it is not straightforward...

[CAEdevice]

Hi Julien,

I was using Paraview 4.1, so after unistalling it, I installed Paraview 3.98.
In that case the simulation stoppes after a few seconds: "pvbatch can not be found"

[julien.decharentenay]

Hi Julien,

I was using Paraview 4.1, so after unistalling it, I installed Paraview 3.98.
In that case the simulation stoppes after a few seconds: "pvbatch can not be found"

Where is ParaView 3.98 installed? In my case it is installed in (and it is found automatically):

Code: Select all

C:\Program Files (x86)\ParaView 3.98.0

[CAEdevice]

I don't remember exactly, but it was the x64 release, so I think it has been installed in default "program files" directory.

[julien.decharentenay]

Can you let me know where it is installed? Did you try the command line I mentioned earlier?

[CAEdevice]

ok, I'm sorry but I'll not be in the office untill monday and my home workstation has left me after seven years of heavy computing

[julien.decharentenay]

I am sorry to hear... It is always annoying when this happens - it is never a good time. Let me know on monday.

[MadMatt]

Matteo time for a new machine? Get the i7 4770K, it is a nice CPU and I am running CFD on a 4.2 millions cells model in 9h45 with 3000 iterations I have now upgraded the cooling to water, so I could overclock the CPU and now I am running the same 3000 iterations in 7h15!

[cdsavage]

Regarding the 2015 calendar, we are announcing that the season will consist of 6 rounds, spread over a longer time period compared to 2014. These are the submission dates for each round:

R1 - 2nd April (high downforce)
R2 - 14th May (high downforce)
R3 - 25th June (high downforce)

R4 - 6th August (medium/low downforce)
R5 - 17th September (medium/low downforce)
R6 - 5th November (medium/low downforce)

At the moment, the intention is for 2 out of the 6 rounds to be non-points scoring, 'practice' rounds. The actual tracks for each round are TBA, but we are aiming for the tracks within each of the 2 groups to all be close together in setup requirements.

We also have an optimal COP number decided, though we need to check a couple of things before we release this.

A release candidate rulebook should be available some time this week. There aren't any major changes since the December 30 release, the changes that have been made are mostly what's been discussed in this thread.

[MadMatt]

Excellent Chris, Why not using R1 and R4 as practice runs? That would be a good idea to gauge the cars and check that all parameters and details are working ok.

I hope there will be a tutorial at some point to be able to do the CFD with the tools mentioned here, because I still have no idea how to do this