[MVRC] Mantium Virtual Racecar Challenge 2018

[wpsiatwin]

At least you have a good basis with the CAE Device bodywork...

Yeah, I tried designing my own completely from the ground up but that was a very slow process and I had to switch back over to that bodywork last minute. I'm hoping to have it completed for the next race. Do you know what the reason for lmp cars moving away from the front heat exchangers was? Rules change?

[machin]

I can only imagine that mid-mounted radiators have some advantage, since front-mounted is not prohibited.... Definitely the chassis are narrower now, which gives room for mid-mounted radiators... It could be something simple like; mid-mounted radiators are less vulnerable to damage...? They also require less pipe work, and reduce the moment of inertia, but those last two would have a really low impact on performance...

Let's see what Variante can do with front mounted radiators!

[variante]

The idea for this configuration was pioneered by team TF (where is him? won't he participate this year?), which in turn comes from the Nissan GTR Nismo.

A little while back pretty much all Le Mans Prototypes had front heat exchangers, here the Ferrari 333SP:-

https://i.wheelsage.org/image/format/pi ... _sp_20.jpg

I totally forgot about those prototypes! I too wonder why they moved away from them... Probably there's a nice technical explanation, but possibly fashion and trends prevailed once again in motorsport
BTW our car layout (TF's and mine) were really identical in layout to the Nissan GTR Nismo: front radiators with dedicated channel venting as soon as possible, and front wing with dedicated channel buried inside the bodywork and ending at the back of the car.

[wpsiatwin]

Is the GTR nismo the road car or the front wheel drive lmp car?

[CAEdevice]

Hxs in the middle of the car reduce inertia, but the MVRC model does't consider inertia

About the rule check: I am not sure to have well interpreted the rule about the carbody in front of the rear wheel. It is a small volume but it quite important about the inwash control.

[machin]

Is the GTR nismo the road car or the front wheel drive lmp car?

It’s the FWD LMP1 that Variante is referring to...

Aerodynamically it was an interesting car... but in an era when everyone else was trying to share the load amongst the front and rear tyres equally that Nissan decided to heavily load up the fronts... and then wondered why it chewed up front tyres!

They also made a big song and dance about only requiring a single element rear wing to balance the front (which was true since most of the mass was up front)... problem was they came to Le Mans and found they were woefully low on FRONT downforce as well... so instigated a hasty body kit to resolve that and quietly stuck on a dual element rear wing to balance it!

...and then the hybrid system didn’t work...

[LVDH]

Maybe the solution is not that difficult: The mid layout is simply better. I assume that the better the understanding and importance of aerodynamics and downforce, the aero guys ran into a similar problem all you guys have now painfully learned. Finding front downforce is pretty difficult. Real cars get designed for the whole season. While it might be possible to design a car with mid downforce levels but good efficiency with front radiators, it is hard to design a balanced car for high downforce tracks with that same front layout. So if you can not just delete everything and start from scratch for every race, like we can but have to use the same base all season, maybe the mid layout is the only good option.

In other news, it looks like the track conditions in Le Mans will not allow the race to take place this Sunday. We will have to wait for the full results until next Sunday. The misty conditions have however allowed to visualize the wing tip vortices on the rear wings pretty well. Soon I will release some images of that.

[roon]

Is the GTR nismo the road car or the front wheel drive lmp car?

It’s the FWD LMP1 that Variante is referring to...

Aerodynamically it was an interesting car... but in an era when everyone else was trying to share the load amongst the front and rear tyres equally that Nissan decided to heavily load up the fronts... and then wondered why it chewed up front tyres!

They deleted the rear drivetrain at some point during development. I don't know why they didn't shelve the project at that point. Was supposed to use high driveshafts on the rear axle and drop gears/portal axles. An unintentionally FWD LMP car was never gonna fly at Le Mans... The power to weight ratio of the mechanical KERS system should have been good.

The original aero and chassis concept was reasonable. Front biased drive and narrow rear tires for reduced blockage, plus the double diffuser to end all double diffusers. Expansion volume behind that car was... expansive.



Keep in mind everything you see above is diffuser exit, plus the wheel well venting to either side.

[machin]

The original aero and chassis concept was reasonable.

Sure, it would’ve been great... if you ignore the tyre loading issue I mentioned. Even without the additional hybrid power it was still chewing up the tyres.

As Variante says; the aero concept was interesting... even if they did underestimate the downforce they needed (even at a low downforce track like Le Mans).

I must say I did find the whole program quite arrogant; the designer was in all the press saying how he’d found a “loophole” in the rules that all the other teams had missed... but it turns out he’d missed that tyre issue; even though it was a hot topic at the time with Audi, Porsche and Toyota all developing their cars to allow them to quadruple stint their tyres... which just goes to show, you can easily become blinkered when you think you have a good idea, and forget that a good car has to do everything well, not be a one trick pony... for me that’s the main lesson people show learn from that Nissan LMP1...

[machin]

We've had a few cars out on track and our spotters on the Mulsanne straight are reporting that the JJR racing car looks quick in a straight line...

[CAEdevice]

Hi, there is an article with interesting numbers on Racecar-engineering (September 2018, page 45). It is about cooling flow on F1 (strangely it is not an article about Formula Student).

The numbers roughly confirm our flow rate, but I think it would be interesting the separate the water cooling from Oil/Ers.

The average water cooling flow is around 1kg/s, ERS + Oil cooling is around 1.2kg/s (total 2.2kg/s, considering high efficiency engines).

I think the data are referred to the average track speed, but I am not sure: can anyone confirm?

[machin]

...but I think it would be interesting the separate the water cooling from Oil/Ers.

Interesting... What do you think the competition would gain from separating these out? I would have thought brake cooling would be the first thing to add, and I'm not entirely convinced adding that would be a good thing: there is already a lot for someone new to try and understand and develop.... My personal view is that the current balance between realism and accessibility is pretty good....

[CAEdevice]

...but I think it would be interesting the separate the water cooling from Oil/Ers.

Interesting... What do you think the competition would gain from separating these out? I would have thought brake cooling would be the first thing to add, and I'm not entirely convinced adding that would be a good thing: there is already a lot for someone new to try and understand and develop.... My personal view is that the current balance between realism and accessibility is pretty good....

I am not sure, because I would need to test the difference while designing a new car, but I remeber that when the new cooling simulation was introduced (passing from KVRC to MVRC) the realism and the technical level of the competion improved. Yes, brake cooling would be the first think to think about.

Accessibility is a good point. I think that the better way would be to provide a standard bodywork (everything that is included between the wheels axles).

[etsmc]

I personally think that brake cooling should be simulated and the option of splitting up the cooling components (cooling radiator, oil, inter-cooler etc).
Yes the competition is about the aerodynamics but cooling is something that has to be considered during the design, will it add complication, most definitely.

How could you make this accessible?
Possibly the intro class can have the intro car or bring your own design but has the same requirements as now lower power engine requiring the simulation of HX, intake and exhaust only.
The Open class has the addition of the brake and other cooling simulations.

just off the cuff ideas.

I am looking forward to put this first race behind me, recent test results are showing big improvements in the car.

[machin]

How could you make this accessible?
....the intro class....

Good point... and actually the Intro class hasn’t been the success I thought it would be... which does surprise me; I thought there would be a lot of people who would want to design their own aerokit without the need to design the cooling... but it turns out not... is this because we currently have Le Mans style cars, and not F1 cars? Is it because the design process is still quite laborious (as in real life)?

It would be interesting to hear from non-competitors who browse this forum to hear what changes would entice them to enter?