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Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 10 Sep 2016, 16:38
by Alonso Fan
On the html report, it says the cop in all 3 directions. Is this the real cop?

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 10 Sep 2016, 17:16
by LVDH
Not sure what you are looking at but the report does not contain any numbers, so there is no CoP.

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 10 Sep 2016, 17:48
by CAEdevice
The post processing is great, congratulations to MantiumCAE!

On the other side, I am very disappointed about my car (it is not a matter of numbers).
It seems that some "extreme" details that worked with OCCFD settings doesn't work with the new evironemnt (and this is a good thing from the point of view of realism).

Can I ask LDVH wich are the main changes about settings, mesh and parameters between the case generated by WFlow and by OCCFD? I know... I could open the "System" directory, but OI am at home and I don't have any old simulation with me.

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 10 Sep 2016, 18:40
by LVDH
CAEdevice wrote: Can I ask LDVH wich are the main changes about settings, mesh and parameters between the case generated by WFlow and by OCCFD? I know... I could open the "System" directory, but OI am at home and I don't have any old simulation with me.
Well the mesh is similar to what you had in respect to mesh resolution. But now we have about 5 surface layers and for snappyHexMesh with a good coverage. These 5 extra layers help to resolve what is happening close to the walls much better. This means that esp. separation is now simulated better. My plan for next year is to switch to second order accurate equation solving. That will then make everything much more realistic. For now I left it at first order because I did not want to change too much from KVRC and because I did not exactly know what kind of CAD quality I could expect from you guys. But as the CAD quality was actually very good and the one car that had bigger problems will be much better next time I am very confident that we will be able to make that switch next season.

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 10 Sep 2016, 18:43
by Alonso Fan
I'm referring to this in the html file

Image

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 10 Sep 2016, 18:45
by CAEdevice
LVDH wrote:But now we have about 5 surface layers and for snappyHexMesh with a good coverage. These 5 extra layers help to resolve what is happening close to the walls much better. This means that esp. separation is now simulated better
Yes, it is exactly what I was talking about!
LVDH wrote:My plan for next year is to switch to second order accurate equation solving. That will then make everything much more realistic. For now I left it at first order because I did not want to change too much from KVRC and because I did not exactly know what kind of CAD quality I could expect from you guys. But as the CAD quality was actually very good and the one car that had bigger problems will be much better next time I am very confident that we will be able to make that switch next season.
If a general "tuning" of the simulation (inlcuding 2nd order) and less rules about the inlets/outles areas would proposed after the second race, I would completely agree!

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 10 Sep 2016, 19:18
by LVDH
Alonso Fan wrote:I'm referring to this in the html file

http://i68.tinypic.com/2en865z.png
It is a slice through the 3D filed in X-direction at x=-1.5m.
Cp is the dimensionless static pressure coefficient. There is no "o" between the "C" and the "p" by the way.
I hope you noticed that you can click on those small balls below the pictures.

CAEdevice wrote:
If a general "tuning" of the simulation (inlcuding 2nd order) and less rules about the inlets/outles areas would proposed after the second race, I would completely agree!
If too much stuff gets changed something that politicians call "unintended consequences" happens. So I will not change too many things. But for the low downforce races I see good chances of relaxing the cooling rules.

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 10 Sep 2016, 19:20
by CAEdevice
Is only my impression or the importance of efficiency is growing up race after race? (This would be a good question for Machin)

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 10 Sep 2016, 19:23
by Alonso Fan
Thanks for explaining

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 10 Sep 2016, 21:13
by CAEdevice
I was wondering if the reports are generated using Paraview and surfaceLIC: I am still having problems with SurfaceLic and the latest release of Paraview. I would try with an older release, but before unistalling I would like to be sure that ising a "decomposed" case is not related with surfaceLIC crash.
Another point is: wich is the difference between "MPI" and "not MPI" release of Paraview?

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 10 Sep 2016, 21:54
by Alonso Fan
What is the css file and what does it contain?

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 10 Sep 2016, 21:59
by CAEdevice
Alonso Fan wrote:What is the css file and what does it contain?
CSS = cascading style sheets

It is where the graphic settings of the html report are stored: nothing to do with the simulation.

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 10 Sep 2016, 22:47
by Alonso Fan
Cool

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 11 Sep 2016, 12:07
by variante
Does anybody know how to produce, in Paraview, streamlines on the surface of the car?? ...and velocity field as well

Setting the "velocity" parameter directly on the car surface produces a uniform "zero velocity" surface (as it should be); also, the surface streamlines are not the required ones.
Offsetting the surface of the car by a few mm (or by a few mesh cells) should do the job, but I don't know how to do that in Paraview.

Re: [MVRC] Mantium Virtual Racecar Challenge 2016

Posted: 11 Sep 2016, 13:10
by Alonso Fan
compliance check complete, only a couple of minor issues. waiting for the numbers now! :D