[MVRC] Mantium Virtual Racecar Challenge 2018

[machin]

Yes, my general remark is that those near the top gain more by increasing downforce, those further back gain more by decreasing drag...

...But as you confirmed, it is easier said than done! Good luck!

[etsmc]

I just ran a few cars through Virtual Stopwatch, and most (but not all) of the round 1 cars would be quicker around Sepang if they reduce drag, compared to increasing downforce...

Keeping efficiency constant, right?

...of course, that doesn't tell you whether it is easier to decrease drag compared to increasing downforce...

Reducing drag is very difficult without incurring in a huge CoP shift. For example, reducing Rear Wing for less drag is easy, but reducing Front Wing doesn't necessarily translate into less drag (given the same efficiency).

Also, if you already are at the point of maximum efficiency of your car, reducing drag will also reduce efficiency, so you don't want to exaggerate even if you were to race at Monza.
My car is currently above the point of maximum efficiency (=more downforce, more drag than ideal), but I can't tune it down too much because my CoP would shift towards the front a lot. And if I try to correct the CoP shift with less Front Wing, the car gets less efficient...

So right now I'm finding easier to gain performace translating the point of maximum efficiency upwards, thanks to new geometries that produce more downforce with similar drag.
If I had to focus on drag reduction, I'd go for front wheel covers, mirrors, canopy,... all those elements that don't have a huge impact on downforce and CoP.

Thanks for tips on where to start looking to reduce drag.
I usually do most of my simulations on the MVRC-fast option till i am at a point that i am happy with my changes then i do a test on the MVRC-Long setting.

my latest results on the long setting are
cd=0.883
cl=-3.612
cl/cd=-4.091
cop=1.66

So looks like i am edging closer to my goal of catching up with PurePowerRacing just need to decide if i can reduce the drag anymore or try and add downforce without the drag...

my front suspension cover is going to be my next target as it is the only thing with a cl/cd that isnt negative.

Edit:

Here is an image from the last run. Anyone care to share their opinion?

[CAEdevice]

Hi etsmc, it looks that there is some space in front of the lower part of the front wheels. You should work on this, in order to reduce the inwash.

Which is the angle of attack of the diffuser? Try to keep it in a range between 15° and 20° (or a bit more if you are playing with vortices and rake angle).

And the distance of the external strakes from the internal side of the diffuser? I have the suspect that there is not enough space to generate the side vortices (the flow form sides and rear wheels inwash goes directly in the central channels)

The car looks well designed.

[machin]

Anyone care to share their opinion?

Have you tried aligning the diffuser strakes more in-keeping with the flow direction (particularly near the throat, front part, of the diffuser), rather than keeping them straight? I.e so the outer ones follow the shape of the inside surface of your rear wheel fairings...

[Ft5fTL]

Anyone care to share their opinion?

Have you tried aligning the diffuser strakes more in-keeping with the flow direction (particularly near the throat, front part, of the diffuser), rather than keeping them straight? I.e so the outer ones follow the shape of the inside surface of your rear wheel fairings...

https://lh3.googleusercontent.com/7qyK7 ... JsAzX2UFLY

Where is TF and Idadox btw?

[machin]

I don't think they signed up this year...

[Team_Bart]

Hi, how is the development going?

I just had a little chat with Bart (Team chief and Technical director at Team Bart) and asked him this question. While he was talking about a possible press presentation somewhere next week, I still managed to get some reaction. Bart: "While we had some problems with the calibration of our windtunnel last week, it seems those problems are fixed now, with thanks to the of commitment our technical partner MantiumFlow and our sponsor CAE Device." Unfortunately I was not allowed to visit the windtunnel, neither he wouldn't tell me what was wrong with it. At this moment the latest prototype is tested there right now, he told me. "We are a bit behind schedule, so we are in a big hurry to catch up with our development plan. Anyway these struggles are part of the game when you are joining a high level competition like the Mantium Virtual Racingcar Challenge with a complete new team", according to Bart. "Still we are happy with the results up to now. It seems we have found some downforce and I am confinced we can fix the ballance issue we experienced at Le Mans." Unfortunately, he wouldn't tell me anything about the numbers of the car: "I can't tell you anything about the car itself, I'm not crazy, I know I would find those numbers within an hour on f1technical.net" he was joking. When asking him about the goals and expectations for the next round in Sepang, he was quite conservative: "At this moment it is very difficult to say where we are at Sepang. In Le Mans we where lucky to not finising last, however it where some welcome points! I think we have to be very happy if we can finish in Sepang on P6 again. Anyway, I'm quite sure MercuryMotorsport and Tulip Racing will make some big steps as well. It would be nice if we can close the gap with the top 4 teams a bit, but I think it is very unlikely that we are able to compete with them in Sepang. I'm very interested in how much performance they've found the last month. In theory we should be able to make the biggest steps, since our car was the slowest last race." He was finnising our conversation. When I was going home I heard some mechanics speaking about the Butterfly-version. I didn't hear that name ealier, they could be pointing to a B-specs car already??

[CAEdevice]

Hi, how is the development going?

I just had a little chat with Bart (Team chief and Technical director at Team Bart) and asked him this question.

Great! You have the best press office!

[Team_Bart]

Great! You have the best press office!

Thanks, I'll them tomorrow morning

By the way I've a small question, it is allowed to have thin features in front of the front wheel centerline, right?

[CAEdevice]

Great! You have the best press office!

Thanks, I'll them tomorrow morning

By the way I've a small question, it is allowed to have thin features in front of the front wheel centerline, right?

I think so, once compliant with the 10mm thickness rule. What do you mean exactly?

[variante]

Anyone care to share their opinion?

The car looks pretty much ok, and performs well already. I think it has a good potential. Here some tips:

[Team_Bart]

I think so, once compliant with the 10mm thickness rule. What do you mean exactly?

I was thinking it was allowed to put thin fences (like 1mm thick for example) in the front and rear diffuser, but when reading it again, I think this was wrong. It is allowed to make them thinner, but they have to be 10mm thick somewhere and for 2/3 of its length at least, am I right?

[machin]

Here some tips:

More of this kind of stuff!

[etsmc]

Thanks for your input i will try and get some more images in a bit and post up to show you some of the actual airflow in the areas you have suggested changes.

I will have a go at the diffuser strakes but not confident in getting a nice curved shape easily in sketchup and having it matte with the diffuser properly.
The parachute probably needs a better image to show what is going on. the design idea was taken from the intro car cover i was hoping that the flap on the front wing/diffuser and the rear of the suspension cover would work together to draw air up from under the front wing/.diffuser.


Edit:


so this shows my parachute the airflow at the diffuser entry and a cross section of the diffuse near the outside edge.

Diffuser Strakes:
From what others have said i need to have them start angled more following the flow of the air in to the diffuser at the entry, then then curve outwards towards the rear
This will help with the airflow staying attached to the diffuser roof at higher angles showen in the cross section of the diffuser

The Parachute:
Should i be extending the front of it to align more with the airflow or is it just too much of a choke point over the flap of the front wing?

[etsmc]

so i have completed a couple of the easier ones suggested by variante, matteo and machin
reduced end plate cord near the body
reduced the main flap of the rearwing by roughly 1.5 deg
created a curved difuser strake, removing the long straight nearest the wheel and placing the curved one slightly more inboard.

Decided that i am not going to see the results today so ran a long test rather than the fast. this will give results i can compare to the ones posted above.