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Re: [MVRC] Mantium Virtual Racecar Challenge 2019 (Grand Prix Cars)
Posted: 12 Aug 2019, 13:43
by machin
wb92 wrote: β12 Aug 2019, 11:09
No I mean for STL creation if I can trim surfaces to each other and leave out ones which won't be used to be sure that there won't be any unnecessary holes in bodywork.
Yes; you can trim parts so that they don't overlap eachother ... I guess that's what you mean?
I still haven't made any CFD calcs, as a newbie need to get some more details
I feel like I could spend hours on modelling details.
It will be interesting to see your car... As Matteo (CAEDevice) said before; the main priority for performance should be to make sure that your wing and diffuser surfaces are working properly... The little details
may have little performance benefit (depending on how little they really are)....
Re: [MVRC] Mantium Virtual Racecar Challenge 2019 (Grand Prix Cars)
Posted: 12 Aug 2019, 13:46
by wb92
I have some small rounds, as I didn't know how much details I should bring to the model and which will have some aero influence
Re: [MVRC] Mantium Virtual Racecar Challenge 2019 (Grand Prix Cars)
Posted: 12 Aug 2019, 13:53
by machin
I was just trying to dig out some old images from the KVRC F1 days to show the level of detail necessary for a front-running design... but it's quite difficult to dig back that far... anyone got any pictures to hand?
There's a few images in this document:-
http://www.sabalcore.com/pressreleases/ ... irtual.pdf
EDIT: Here's a good one:-

Re: [MVRC] Mantium Virtual Racecar Challenge 2019 (Grand Prix Cars)
Posted: 12 Aug 2019, 14:07
by wb92
okay I think I've found the way to get size under the control, but I'm afraid if more parts would come that would be more annoying to get below that size limit.
Do I also have to add within STLs halo, helmet, exhaust, etc?
Re: [MVRC] Mantium Virtual Racecar Challenge 2019 (Grand Prix Cars)
Posted: 12 Aug 2019, 14:54
by CAEdevice
The whole CSR Team thread is interesting:
viewtopic.php?t=14949
For the new partecipants: consider that CSR was a very very top car, not the average level
Re: [MVRC] Mantium Virtual Racecar Challenge 2019 (Grand Prix Cars)
Posted: 12 Aug 2019, 15:50
by machin
wb92 wrote: β12 Aug 2019, 14:07
Do I also have to add within STLs halo, helmet, exhaust, etc?
No... we have all that, and in fact we prefer to use our own parts to stop anyone changing those parts...

Re: [MVRC] Mantium Virtual Racecar Challenge 2019 (Grand Prix Cars)
Posted: 12 Aug 2019, 16:32
by LVDH
Actually I told someone that the 80MB limit is only for the parts you are required to submit. That is how I understood the rule and as they should be the same for everyone that is how it will be now. I will soon modify the too large provided stl parts. But as this will need some testing they will at best be available for race 2.
And for the race simulations I always use the provided stl files, so they are the same for everyone. Imagine someone would build some trick into his wheels or suspension and I would overlook it. I always delete all these parts and copy my own ones into the simulation. Now writing this, I think we should make it a rule to make sure you guys only send needed data, as deleting these parts takes me my time.
Re: [MVRC] Mantium Virtual Racecar Challenge 2019 (Grand Prix Cars)
Posted: 12 Aug 2019, 22:33
by machin
CAEdevice wrote: β12 Aug 2019, 11:13
The new front wing is very similar to mine. Do you have any data about the simulation?
.
Unfortunately my steam-powered little computer wonβt handle anything like the CFD... so no testing has been done... my only real intention was to make something easy to use and modify... e.g for the front wing I would suggest adjusting the profiles, maybe some strakes could be added underneath...?
Re: [MVRC] Mantium Virtual Racecar Challenge 2019 (Grand Prix Cars)
Posted: 12 Aug 2019, 22:35
by CAEdevice
machin wrote: β12 Aug 2019, 22:33
CAEdevice wrote: β12 Aug 2019, 11:13
The new front wing is very similar to mine. Do you have any data about the simulation?
.
Unfortunately my steam-powered little computer wonβt handle anything like the CFD... so no testing has been done... my only real intention was to make something easy to use and modify... e.g for the front wing I would suggest adjusting the profiles, maybe some strakes could be added underneath...?
Yes, same possibile evolution for my wing, but it depends on the time I will have in the next days.
Maybe LDVH can run a simulation with your car? It would be a good test before the first race.
Re: [MVRC] Mantium Virtual Racecar Challenge 2019 (Grand Prix Cars)
Posted: 13 Aug 2019, 00:31
by wb92
machin wrote: β12 Aug 2019, 13:43
wb92 wrote: β12 Aug 2019, 11:09
No I mean for STL creation if I can trim surfaces to each other and leave out ones which won't be used to be sure that there won't be any unnecessary holes in bodywork.
Yes; you can trim parts so that they don't overlap eachother ... I guess that's what you mean?
machin wrote: β12 Aug 2019, 15:50
wb92 wrote: β12 Aug 2019, 14:07
Do I also have to add within STLs halo, helmet, exhaust, etc?
No... we have all that, and in fact we prefer to use our own parts to stop anyone changing those parts...
That makes it more clear for me, I think with that I can handle proper quality of my STL parts.
machin wrote: β12 Aug 2019, 13:43
It will be interesting to see your car... As Matteo (CAEDevice) said before; the main priority for performance should be to make sure that your wing and diffuser surfaces are working properly... The little details
may have little performance benefit (depending on how little they really are)....
Still some details left, and I hope all of them will work together, but here's small teaser of my car:
I'm also prepared for first-timer scrutineering issues

Re: [MVRC] Mantium Virtual Racecar Challenge 2019 (Grand Prix Cars)
Posted: 13 Aug 2019, 11:11
by LVDH
Hi guys,
A while ago, one of you was nice enough to point out a small error in MantiumFlow. I fixed it and sent out the new version to you. It turns out my "error" was a work-around for an OpenFOAM bug. It relates to the calculation of the centre of pressure. So the complaints I have been getting about strange downforce distribution are correct. I will give it my best to get my Windows environment working again to send out a new version which will have to be used for the first race.
While you are waiting, you can hack a file to get the correct values. After building the case, head over to the
forceCoeffs file in the
system folder of the case and change the line(s):
to
Then you can run the case.
Re: [MVRC] Mantium Virtual Racecar Challenge 2019 (Grand Prix Cars)
Posted: 13 Aug 2019, 13:56
by CAEdevice
Thanks, I thought I was crazy looking at the balance of the car. In the evenng I will see the new results (I modified forceCoeff during the meshing: I shoud have been on time, right?)
Re: [MVRC] Mantium Virtual Racecar Challenge 2019 (Grand Prix Cars)
Posted: 13 Aug 2019, 16:56
by LVDH
CAEdevice wrote: β13 Aug 2019, 13:56
Thanks, I thought I was crazy looking at the balance of the car. In the evenng I will see the new results (I modified forceCoeff during the meshing: I shoud have been on time, right?)
Yes
Re: [MVRC] Mantium Virtual Racecar Challenge 2019 (Grand Prix Cars)
Posted: 13 Aug 2019, 17:35
by rjsa
Where do I set rake?
Re: [MVRC] Mantium Virtual Racecar Challenge 2019 (Grand Prix Cars)
Posted: 13 Aug 2019, 17:42
by TalnoRacing
Here is the TalnoRacing TR19 for this season's challenge. I was not able to run any CFD, so this is a best guess gut feel design. But I had a lot of fun modelling a sleek looking beast.
