[MVRC] Mantium Virtual Racecar Challenge 2017

[LVDH]

Not software related for me.

Good to know. From what I can tell the issue stem from the streamline creation. I think so few people noticed because nobody updated for that small feature. The rotated radiators was a bigger motivation.

Oh, abd the baby sleeping habits get a lot in the way

I guess by now, quite a few people suffer from this. I think almost half of us have this "problem". Soon we can teach them how to build cars.

[rjsa]

Not software related for me.

Good to know. From what I can tell the issue stem from the streamline creation. I think so few people noticed because nobody updated for that small feature. The rotated radiators was a bigger motivation.

Oh, abd the baby sleeping habits get a lot in the way

I guess by now, quite a few people suffer from this. I think almost half of us have this "problem". Soon we can teach them how to build cars.

I'm still running an elder version. I suffer a lot from processing time, so I'm putting the streamlines for later. The time to need to rotate the HX is coming close though.

[rjsa]

Wow! Not bad!
I know it's frustrating not to gain much after so many simulations, but -at least from my experience- it is still possible to learn a lot from mistakes (even more than during those times when everything goes right).

I learned that I maxed out the floor, the only way to improve rear difuser is to reduce the front one.

Now I need to figure a way to feed more air to the back.

[LVDH]

Best is always to have a good and detailed list with all the runs and one column explaining what changed in the geometry compared to which run. After reading it a few times you might come up with new ways to improve the car. Question is, if you are organized enough for such a list.

[variante]

Wow! Not bad!
I know it's frustrating not to gain much after so many simulations, but -at least from my experience- it is still possible to learn a lot from mistakes (even more than during those times when everything goes right).

I learned that I maxed out the floor, the only way to improve rear difuser is to reduce the front one.

Now I need to figure a way to feed more air to the back.

My diffuser works the opposite way: less air coming from the front improves its performace. So having the biggest front diffuser/wing is the way to go for my layout. Airflow comes almost exclusively from the sides of the car.
It's a well developed solution, and I know other people adopt it... you might want to explore it

[rjsa]

@andre, yep, I have it all logget.

@variante, I've seen you don't have a full flat floor between the wheels, It's on my list.

[LVDH]

The cars are out:

The slider can be found on the challenge page:
http://mantiumchallenge.com/cars-mvrc-sau_paulo-2017/

Getting the air in from the sides is the true trick with these cars. It is not knowledge exclusive to that brilliant Italian mind with the unconventional MVCR cars. Germans have figured that out quite a while ago:

[CAEdevice]

Getting the air in from the sides is the true trick with these cars.

For Le Mans I'm working with the opposite target: I am trying to seal the sides with vortices.
At the moment it doesn't work... but I am convinced it is a good way to have df/dr above 7.00.

What I have learnt from MVRC is that there is not a perfect concept, but only "refined" or "less refined" ideas.

[machin]

What I have learnt from MVRC is that there is not a perfect concept, but only "refined" or "less refined" ideas.

Yes, I like that; it reminds me of the difference between the big bulbous nose on one of the Renault F1 cars a few years back compared to the slender noses on the other cars... Both solutions worked although they were polar opposites....

Having said that; clearly you could have a really bad idea that won't work no matter how hard you refine it!

[CAEdevice]

What I have learnt from MVRC is that there is not a perfect concept, but only "refined" or "less refined" ideas.

Yes, I like that; it reminds me of the difference between the big bulbous nose on one of the Renault F1 cars a few years back compared to the slender noses on the other cars... Both solutions worked although they were polar opposites....

Having said that; clearly you could have a really bad idea that won't work no matter how hard you refine it!

Do you mean Renault R29 and R30? Their nose remembered me the Benetton of the Schumacher period.

About our design "concept": the worst thing to do is to is copy a single detail without understanding the general flow around the car. At the beginning of the development of my car (2014) I was inspired by Audi and Toyota LMP1s, now I can only go on with my own development because the differences bettween our floor and LMP1 "standard" floor influence every area of the car.

I am very curious about JJR car (he has never done a disapponting race since the very beginning of KVRC/MVRC challenge): I tried to copy some details but they definetly don't work with my design.

[JJR]

Actually I have had a couple of disapponting races most on efficient tracks and never win any

... and sadly TF is missing

I have made some progress but I think it will be not enough to catch Matteo. I never know because
I ´m not using MantiumFlow.

I ´m curently doing CFD modelling of nascar car and if I find some time I will do also CFD of Ford ZAKSPEED Group 5 car from 1982. It was absolutelly beast in its times running in DRM.

[CAEdevice]

I did not notice the absence of TF. What happened?

[AratzH]

Some manufacturing issues prevented me from finishing the car in time

I'll focus on Le Mans now.

[LVDH]

My diffuser works the opposite way: less air coming from the front improves its performace. So having the biggest front diffuser/wing is the way to go for my layout. Airflow comes almost exclusively from the sides of the car.
It's a well developed solution, and I know other people adopt it... you might want to explore it

Without really knowing it for sure I think the choice between a floor that draws air from the front (and profits from the sides sealed) and one which gets the air from the sides is a question of how much resistance the air sees traveling through the floor and how good the diffuser sucks air through this bottleneck. Usually in aerodynamics it is good to derive some dimensionless number. I just came up with this:

Diff_factor=((V*h^2)/(l*nu))*((e-e_id)/e_id)^2

With:

• V - velocity

• h - floor height

• l - length of floor

• nu - kinematic viscosity

• e - expansion factor diffuser

• e_id - ideal expansion factor

The idea is that more air velocity and a higher floor help to get air through the floor and a longer length and higher viscosity make it harder. The part with the expansion factors is about how well the floor is designed. The closer you are at the ideal expansion the more you will force through the floor.
I assume that if the Diff_factor is above a certain number, you go for an F1 style diffuser which draws air from the front and below a certain factor you have to get the air from the sides. The question is why you cannot do both.

[Ft5fTL]

Getting the air in from the sides is the true trick with these cars. It is not knowledge exclusive to that brilliant Italian mind with the unconventional MVCR cars.

I did figured that out on the last years efficiency races and optimized the car accordingly. Sadly this year i couldnt find a way to do that on a desired level.

This will be my last submission for this years competition. I'm using the same car for the last race aswell. I will serve my mandatory military service starting tommorrow. It will end around april 18th (i hope i will be here for the next years competition). So take care everyone.