[MVRC] Mantium Virtual Racecar Challenge 2019 (Grand Prix Cars)

[Koldskaal]

hehe, my numbers are showing around 110% cooling. Remember WB-racing in Singapore got 98% with inlets smaller than mine are now.

It's not only about size of the inlet Actually I may have also >100% of cooling with such small inlets, and in theory it could be smaller ^^. Keep in mind that I started the season with awful engine power, so I had bit more work to get it right beside balance and other stuff.

Yeah, it really is the case that size doesnt matter as much as how you use it
A large part of it is to simply point the inlet in the right direction to avoid recirculation ahead of the radiator.

[etsmc]

here is an image of my floor and the flow.
I have created 3 monitoring surfaces as follows:
- Floor Entry across the leading edge of the floor and only as high as the lower surface of the floor
- Diffuser entry across the rear of the floor before the start of the diffuse, again only as high as the lower surface of the floor
- Frontwing entry is across the leading edge of the front wing and only as high as the lower surface of the wing

Thinking i should maybe do another one for the diffuser exit but this is what i have now.

you can see from the floor entry image how the wake is getting pushed out, is this enough or should it be more?
and the diffuser entry showing only flow from the floor so must be sealing the floor somewhere.

[Koldskaal]

Now i wouldnt call myself an expert, at all. I am also trying my hardest to understand whats really going on. Anyway this is what i see:

https://ibb.co/2kDZGys

It seems that a large portion of your floor is affected by the tyrewake. I would try to correct that.

[wb92]

hehe, my numbers are showing around 110% cooling. Remember WB-racing in Singapore got 98% with inlets smaller than mine are now.

It's not only about size of the inlet Actually I may have also >100% of cooling with such small inlets, and in theory it could be smaller ^^. Keep in mind that I started the season with awful engine power, so I had bit more work to get it right beside balance and other stuff.

Yeah, it really is the case that size doesnt matter as much as how you use it
A large part of it is to simply point the inlet in the right direction to avoid recirculation ahead of the radiator.

And to avoid separations in front and inside the duct, in terms of outlet you need to be sure that you have enough 'outlet area'

here is an image of my floor and the flow.
I have created 3 monitoring surfaces as follows:
- Floor Entry across the leading edge of the floor and only as high as the lower surface of the floor
- Diffuser entry across the rear of the floor before the start of the diffuse, again only as high as the lower surface of the floor
- Frontwing entry is across the leading edge of the front wing and only as high as the lower surface of the wing

Thinking i should maybe do another one for the diffuser exit but this is what i have now.

you can see from the floor entry image how the wake is getting pushed out, is this enough or should it be more?
and the diffuser entry showing only flow from the floor so must be sealing the floor somewhere.

could you also show U Near wall from the bottom? That's more useful than streamlines

[etsmc]

here we go

[Koldskaal]

I think that it is very generous of you to share such a revealing picture . On the subject of what to do about the tyre wake, this image doesnt say much in my opinion. Try to have a look at the cp_tot Z-slices especially the z=-0.3m. If the tyrewake is visible under the floor in that image, you should try to mitigate that (I suspect that it is, see my earlier comment). You also seem to have a few separation bubbles on the rear- and front wing. Getting rid of these would probably improve performance quite a bit.

[Alonso Fan]

Are we getting the results today?

[machin]

Are we getting the results today?

As with the previous rounds this season; the results will be published next weekend to coincide with the real Japanese Grand Prix.

[Alonso Fan]

Ah no worries

[etsmc]

I think that it is very generous of you to share such a revealing picture . On the subject of what to do about the tyre wake, this image doesnt say much in my opinion. Try to have a look at the cp_tot Z-slices especially the z=-0.3m. If the tyrewake is visible under the floor in that image, you should try to mitigate that (I suspect that it is, see my earlier comment). You also seem to have a few separation bubbles on the rear- and front wing. Getting rid of these would probably improve performance quite a bit.

Well from what i can see the tyre wake is just seeing the very corner of the front edge of the floor

-0.280m is as low as my slices go so maybe i need to up the number of slices. (I could do this in paraview but ehh its late )

revealing pictures yes they might reveal my car but we have seen in the past you cant just go and copy a bit from someones car and expect it to work. I tend to run in the midfield in these challenges and i hope some of what i show and more so the advice people give will help other behind to close the gap..

I have made some changes based on other advice given so will see how that goes.

[etsmc]

Made some suggested changes and to my front and rear wing and it certainly improved the efficiency of them but now I have to rebalance the car as it has shifted forwards a lot.
I have not got the results on me but will post some pics later if I can.
Big thanks to @wb92 who gave some advice.

[etsmc]

Here is the updated image after the adjustments to the front and rear wing.

to my untrained eyes i could probably improve the rear wing a touch more as it looks like some separation issues still??
I am guessing that the focus now should be more on the leading edge of the floor? Not to sure how to go about this as its hard to find any ideas/concepts but thinking as wb92 suggested in pm to look at the t tray area. I guess implying i could feed the air from there under the floor?

some number for comparison
Before
Force Coefficients averaged fw - Cd: 0.136, Cl: -0.584, Cl/Cd: -4.295, Cl(f): -1.782, Cl(r): 1.198, CoP: -
Force Coefficients averaged rw - Cd: 0.060, Cl: -0.305, Cl/Cd: -5.080, Cl(f): 0.511, Cl(r): -0.816, CoP: -
After
Force Coefficients averaged fw - Cd: 0.136, Cl: -0.670, Cl/Cd: -4.929, Cl(f): -2.050, Cl(r): 1.380, CoP: -
Force Coefficients averaged rw - Cd: 0.050, Cl: -0.264, Cl/Cd: -5.251, Cl(f): 0.442, Cl(r): -0.705, CoP: -
and the CoP for the whole car shifted forward 0.5m

[jjn9128]

So I found myself thinking about F1 rules through the ages for a front page article which will probably never see the light of day - the idea might have been interesting but what I wrote was certainly not. Anyway I came up with this - it's an amalgamation of a couple of eras of F1 rules with a "ground effect" floor (orange surface denotes minimum height for Venturi) and an aeroscreen instead of a halo - what do people think about this as an idea going forward? It's open wheel but incorporates future ideas. The only thing I thought might be better is scope for front wheel pods like Formula E. It also fixes the minimum cockpit dimensions (using the actual F1 rules) which annoyed CAEdevice and myself early on .

Obviously rules are in the hands of the rule makers but I wondered what everyone thought.





It still needs gearbox/engine plenum/exhaust/suspension...etc It also currently has lower profile than the 2021 F1 18" rims&tyres but mismatched like Formula E, so 240/660-18" front and 315/680-18" rear but that could easily change to the F1 sizes if that was desired.

[wb92]

Forget about wheelpods like Formula E; actually Formula E is closer to kinda aggressive open-GT car, e.g. BAC Mono or Caparo T1. In terms of tyres they use road version of Michelin Pilot Sport (because they race on... public roads...). As far as I remember, probably Buemi said that 2nd gen. F-E car has less downforce than 1st, but it's quicker due to e-motors, batteries and tyres. So any aero F-E solutions, please - no. I've seen the car live few times very close and it has more design than aero.

Aeroscreen is interesting, but full closed cockpit would be better idea for many reasons in reality. Also for competition like MVRC - why we would need to calculate volume underneath the transparent screen?

[jjn9128]

Forget about wheelpods like Formula E; actually Formula E is closer to kinda aggressive open-GT car, e.g. BAC Mono or Caparo T1. In terms of tyres they use road version of Michelin Pilot Sport (because they race on... public roads...). As far as I remember, probably Buemi said that 2nd gen. F-E car has less downforce than 1st, but it's quicker due to e-motors, batteries and tyres. So any aero F-E solutions, please - no. I've seen the car live few times very close and it has more design than aero.

Aeroscreen is interesting, but full closed cockpit would be better idea for many reasons in reality. Also for competition like MVRC - why we would need to calculate volume underneath the transparent screen?

I meant the front wheel pods more in the sense of low drag/ controlling front tyre wake to aid floor. I think Gen2 FE has a bit more downforce than Gen1 but it is significantly lower drag, so maybe it is lower downforce.