[MVRC] Mantium Virtual Racecar Challenge 2018

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TalnoRacing
3
Joined: 22 May 2015, 10:50

Re: [MVRC] Mantium Virtual Racecar Challenge 2018

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I've tried a number of different concepts and cannot seem to achieve a front wing Cl > 1 when running a fast simulation. I've analysed diffusers and separate wings, but get the same result. So either the car downstream of the wing/diffuser is not optimised, or my lack of understanding of aerodynamics is greater than what I want to believe....

The car I submitted for this round has its COP at ±2.0m, so I know it is not optimal. The smaller wing angle produced the most downforce for me.

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LVDH
44
Joined: 31 Mar 2015, 14:23

Re: [MVRC] Mantium Virtual Racecar Challenge 2018

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Getting front downforce is really tricky in this championship. Finding a good wing / front diffuser is hard as also the suspension has to be covered. Sorry I cannot give any advice right now.

I just checked all the cars. It looks like I detected quite a few issues. I will have to check my list later to see if they lead to penalties as I think that some are repeated violations. And among the cars that I have to discuss with Richard is the CAEdevice entry. You guys are pushing him to the limit. One of the issues, I could figure out myself, but the other one needs some clarification. Lets see how he gets through this this time...

And keep in mind, you can always protest our rulings within a certain time limit. I do not think we ever specified it but if we made mistakes in the past it is too late to protest now, so if in doubt send us an email right away.

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Team_Bart
2
Joined: 10 Jul 2018, 19:26

Re: [MVRC] Mantium Virtual Racecar Challenge 2018

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For quite a while now I'm wondering how those louvres on top of the fenders are working. Like what I found is that there has to be a high pressure inside the fender, due to the rotating wheel and a low pressure on top of the fender, those louvres should reduce the pressure inside and increase it on top of the fender. I also found that old LMP cars gained quite a lot of downforce with those. Anyway, I tried it a few times in MFlow, but exept from meshing up the flow behind, it didn't affect the lift/drag values of the fender. Do you of anyone else know more about them (JJR :D :D )?


@LVDH, about that warning last race, are you sure you did not get confused by me and Tulip Racing? Since on the scrutineering page his car has my color and he had the issue with the suspension submission? Anyway, I placed a small bulge on the most critical part (I thought it was within the limits) of the front suspension cover, to make sure it is covering everything for sure now :)

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BlakjeKaas
1
Joined: 16 Sep 2018, 18:54

Re: [MVRC] Mantium Virtual Racecar Challenge 2018

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That multi-element design might be very interesting to use, it will however result in more drag, and probably some problems around the suspension, as it will probably needs to be placed a bit higher. This in turn will influence the cooling heavily (or at least in my instance) as I can not seem to make cooling work using sidepods (I get volume flows between 0.5-1.0 m^3/s).

But it can definitely be quite interesting throw a couple of iterations at.
MVRC: Tulip Racing

JJR
JJR
16
Joined: 12 Jul 2013, 20:02

Re: [MVRC] Mantium Virtual Racecar Challenge 2018

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Team_Bart wrote:
15 Nov 2018, 14:09
For quite a while now I'm wondering how those louvres on top of the fenders are working. Like what I found is that there has to be a high pressure inside the fender, due to the rotating wheel and a low pressure on top of the fender, those louvres should reduce the pressure inside and increase it on top of the fender. I also found that old LMP cars gained quite a lot of downforce with those. Anyway, I tried it a few times in MFlow, but exept from meshing up the flow behind, it didn't affect the lift/drag values of the fender. Do you of anyone else know more about them (JJR :D :D )?
Hi Team_Bart, louvres on top of front fenders are working as you mentioned. They help me to shift ballance at front by 2% and gain in total ClA of -0,126. They actually reduced my L/D ratio by 0,1 but I just need that front downforce.

I hope that I done enough to shift ballance at CoG. Im not sure that I done enough to catch Variante and Matteo. I think it is last time I used current car and looking forward to high downforce tracks.
Last edited by JJR on 15 Nov 2018, 15:52, edited 1 time in total.

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LVDH
44
Joined: 31 Mar 2015, 14:23

Re: [MVRC] Mantium Virtual Racecar Challenge 2018

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Team_Bart wrote:
15 Nov 2018, 14:09
For quite a while now I'm wondering how those louvres on top of the fenders are working. Like what I found is that there has to be a high pressure inside the fender, due to the rotating wheel and a low pressure on top of the fender, those louvres should reduce the pressure inside and increase it on top of the fender. I also found that old LMP cars gained quite a lot of downforce with those. Anyway, I tried it a few times in MFlow, but exept from meshing up the flow behind, it didn't affect the lift/drag values of the fender. Do you of anyone else know more about them (JJR :D :D )?
The high pressure inside of the wheel houses not only pushes the fenders upwards but also forces the wheels down. This would actually be quite advantageous. The reason to extract air out of them is to get more air either through the cooling system on car with front radiators or to get more air through the front diffuser. So by just looking at the force values of the fender you might not notice a big difference. But the front down force generating parts might be happy. This depends on the design in front though. If the air has a nice path away from the diffuser, open wheel houses will not change much.


Team_Bart wrote:
15 Nov 2018, 14:09
@LVDH, about that warning last race, are you sure you did not get confused by me and Tulip Racing? Since on the scrutineering page his car has my color and he had the issue with the suspension submission? Anyway, I placed a small bulge on the most critical part (I thought it was within the limits) of the front suspension cover, to make sure it is covering everything for sure now :)
Although I am at least 50% robot, I possibly made a mistake, I can check later.

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CAEdevice
47
Joined: 09 Jan 2014, 15:33
Location: Erba, Italy
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Re: [MVRC] Mantium Virtual Racecar Challenge 2018

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TalnoRacing wrote:
15 Nov 2018, 12:37
I've tried a number of different concepts and cannot seem to achieve a front wing Cl > 1 when running a fast simulation. I've analysed diffusers and separate wings, but get the same result. So either the car downstream of the wing/diffuser is not optimised, or my lack of understanding of aerodynamics is greater than what I want to believe....

The car I submitted for this round has its COP at ±2.0m, so I know it is not optimal. The smaller wing angle produced the most downforce for me.
What about a bit of rake?

BTW: Would it be possibile to define rake with two parameters (front and rear height, btoh avove 50mm). Where exaclty is the rotation point now?

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CAEdevice
47
Joined: 09 Jan 2014, 15:33
Location: Erba, Italy
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Re: [MVRC] Mantium Virtual Racecar Challenge 2018

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LVDH wrote:
15 Nov 2018, 12:59
I just checked all the cars. It looks like I detected quite a few issues. I will have to check my list later to see if they lead to penalties as I think that some are repeated violations. And among the cars that I have to discuss with Richard is the CAEdevice entry. You guys are pushing him to the limit. One of the issues, I could figure out myself, but the other one needs some clarification. Lets see how he gets through this this time...
I am sorry about that. If there is something wrong with the template and you think it can influence the performance, don't think about it twice and give a penalty to CAEdevice.

If there are interpretation issues consider that it's ok to show here any part of the geometry and talk about it.

ex. Rearview mirrors support: the section in the short part inlcuded in the visibility volume has not changed, only the part outside it, that can be considered a part of the chassis, changed (I can provide a STEP where this would appear more clearly than in the STL). I think it is normal to push the limit (just like Ferrari/Mercedes/Rebull in F1) :)

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LVDH
44
Joined: 31 Mar 2015, 14:23

Re: [MVRC] Mantium Virtual Racecar Challenge 2018

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CAEdevice wrote:
15 Nov 2018, 16:16
TalnoRacing wrote:
15 Nov 2018, 12:37
I've tried a number of different concepts and cannot seem to achieve a front wing Cl > 1 when running a fast simulation. I've analysed diffusers and separate wings, but get the same result. So either the car downstream of the wing/diffuser is not optimised, or my lack of understanding of aerodynamics is greater than what I want to believe....

The car I submitted for this round has its COP at ±2.0m, so I know it is not optimal. The smaller wing angle produced the most downforce for me.
What about a bit of rake?

BTW: Would it be possibile to define rake with two parameters (front and rear height, btoh avove 50mm). Where exaclty is the rotation point now?
Unfortunately it is at (0,0,0) and not in the wheel center. Normaly the wheel center should be at (0,0,0). But old carryover from the KVRC days means that it is not there and I simply forgot when starting the new season. As rake is not really used, I never looked deeper into it.


CAEdevice wrote:
15 Nov 2018, 16:22
LVDH wrote:
15 Nov 2018, 12:59
I just checked all the cars. It looks like I detected quite a few issues. I will have to check my list later to see if they lead to penalties as I think that some are repeated violations. And among the cars that I have to discuss with Richard is the CAEdevice entry. You guys are pushing him to the limit. One of the issues, I could figure out myself, but the other one needs some clarification. Lets see how he gets through this this time...
I am sorry about that. If there is something wrong with the template and you think it can influence the performance, don't think about it twice and give a penalty to CAEdevice.

If there are interpretation issues consider that it's ok to show here any part of the geometry and talk about it.

ex. Rearview mirrors support: the section in the short part inlcuded in the visibility volume has not changed, only the part outside it, that can be considered a part of the chassis, changed (I can provide a STEP where this would appear more clearly than in the STL). I think it is normal to push the limit (just like Ferrari/Mercedes/Rebull in F1) :)
Hehe, somehow sounds like you are now nervous and pointing into places I did not even think about. Maybe your car needs even another look. The one thing I found on your car is legal and the other on is only a question of mm, so as long as I do not change my mind over night you will only get a warning. Tomorrow the scruteneering results will get posted online.

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CAEdevice
47
Joined: 09 Jan 2014, 15:33
Location: Erba, Italy
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Re: [MVRC] Mantium Virtual Racecar Challenge 2018

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No problem in case of penality anyway! I was convinced to have reached the limit with my car, but just now, after a crazy experiment, I have find another gold mine. I know it is too late for high efficiency races (and it is not useful for the extreme df races), but it is funny: that is what makes MVRC and aerodynamics so interesting.
Last edited by CAEdevice on 15 Nov 2018, 18:46, edited 2 times in total.

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Team_Bart
2
Joined: 10 Jul 2018, 19:26

Re: [MVRC] Mantium Virtual Racecar Challenge 2018

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Thanks JJR and LVDH for the explanation! Probably I can make a bit better design with LVDH's comments and have at least a kind of benchmark now :)

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CAEdevice
47
Joined: 09 Jan 2014, 15:33
Location: Erba, Italy
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Re: [MVRC] Mantium Virtual Racecar Challenge 2018

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LVDH wrote:
15 Nov 2018, 18:10
Unfortunately it is at (0,0,0)
No problem, the important thing is to know where it is.
Is it on the intersection of the plane that passes thorugh the front wheels axle (and normal to ground) and the simmetry plane, am I right? Just a bit lower.

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CAEdevice
47
Joined: 09 Jan 2014, 15:33
Location: Erba, Italy
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Re: [MVRC] Mantium Virtual Racecar Challenge 2018

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LVDH wrote:
15 Nov 2018, 18:10
Hehe, somehow sounds like you are now nervous and pointing into places I did not even think about.
I am nervous because JJR and Variante are both so near this year :D
It looks as hard as 2016 season, 2017 was to easy to be true.

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LVDH
44
Joined: 31 Mar 2015, 14:23

Re: [MVRC] Mantium Virtual Racecar Challenge 2018

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CAEdevice wrote:
15 Nov 2018, 18:50
LVDH wrote:
15 Nov 2018, 18:10
Unfortunately it is at (0,0,0)
No problem, the important thing is to know where it is.
Is it on the intersection of the plane that passes thorugh the front wheels axle (and normal to ground) and the simmetry plane, am I right? Just a bit lower.
No, but I will check that out now :twisted:

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machin
162
Joined: 25 Nov 2008, 14:45

Re: [MVRC] Mantium Virtual Racecar Challenge 2018

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CAEdevice wrote:
15 Nov 2018, 18:15
...but just now, after a crazy experiment, I have find another gold mine. I know it is too late for high efficiency races (and it is not useful for the extreme df races), but it is funny: that is what makes MVRC and aerodynamics so interesting.
I am intrigued what you have found... is it a big visual change?!

Have we left you stewing long enough over the potential penalty yet? ☺️
COMPETITION CAR ENGINEERING -Home of VIRTUAL STOPWATCH

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