[MVRC] Mantium Virtual Racecar Challenge 2016

[rjsa]

Well, I have a goal, allright. Getting there is something entirely different.

I'm having a hard time getting DF from the front.

[CAEdevice]

I am convinced that you (rjsa) will be a very interesting new entry.
I also hope to find in the next season all the teams and people of the season 2016.

I am considering to run the first race in the "lmp2-like" class, it depends on the scheduling (my priority is the developmemt of the customer car this year) and on the type of the first race (high df or efficiency).

[rjsa]

Thanks for the kind words, I hope to prove them right

[rjsa]

One thing is for sure: starting from published race results is much easier. You know what's possible and how it looks like one gets there. From the scratch must be a whole different challenge.

[LVDH]

Is there any news about the rulebook 2017? The "customer" (or "opensource") car is ready from the CAD modeling point of view, but it needs some cfd testing before being released. I also need to know if I have to "fine tune" it for the top class or for an LMP2 like class.

Hi, I was on a short vacation. The background talking of the MVRC staff has begun and we are working on some of the details now. Before anything meaningful can happen I have to do some tests on the cooling side.
The rules will not change too much but certain templates will be adjusted to make sure you have to design new cars. And there will be a intro class again. This car will be designed either by Chris or CAEdevice or both or even more cars? The important thing will be to get the intro class back.

[CAEdevice]

I think that it would be great to have a lmp2like class with different "factories" ( a car designed by Chris would be exciting).

My idea, after the presentation of the open source cars, is to frozen everything is included between the front and rear axles (to make the rule check easier): the orginal geometry would be deveopled by the "customers", only were allowed, during the season. Simplified mechanics (ex. less engine power to have less cooling requirements) could be considered.

My "customer car" will be provided with different setups (high, medium, low df) and with the possibility to easily fine tune the airfoils.

[rjsa]

I don't know how hard would that be to implement, but being able to twist the HX would bring a new interesting avenue of development. Is that on the plans?

I also would like to understand something. Please pardon my ignorance, when I did it, I did hydrodynamics with an HP calculator, not CFD. Here it goes: I'm confused with the CD / CDxA nomenclature used in the report. What's that number? CDxA or reallly CD and everyone is using 1m2 as area?

[CAEdevice]

Yes the automated report (the html file) uses 1m^2 as symbolic frontal area.

[Alonso Fan]

The rules will not change too much but certain templates will be adjusted to make sure you have to design new cars

I hope its only minor since I'm designing mine based on 2016 rules

[rjsa]

Yes the automated report (the html file) uses 1m^2 as symbolic frontal area.

Tha much I got. What I still can't figure it out is: Are we seeing real CDxA with real CD and fake area OR real CD with fake area and fake CDxA?

[CAEdevice]

Real Cd*A, obtained dividing the force per 0.5*rho*(v^2)... (more or less: 0.5*1.225*44.7^2 = 1224).

Once you have Cd*A, if A=1 m^2, you have a fictional Cd.

[LVDH]

For reasons of simplicity A_ref is used as 1m². In the end we need CI*A_ref anyways so it does not matter what A_ref I use. If I would calculate the frontal cross section of your car to lets say 1.6m² the reported Cd would be lower but the product of the new A_ref and Cd would still be the same.

That passenger car manufacturers advertize with Cd and not Cd*A is just to appear to create more energy efficient cars but as people get older they need to sit upright and compensate for other body parts so they need SUVs which are larger which in the end create more drag even if every generation of cars have lower Cd values.

[CAEdevice]

That passenger car manufacturers advertize with Cd and not Cd*A is just to appear to create more energy efficient cars but as people get older they need to sit upright and compensate for other body parts so they need SUVs which are larger which in the end create more drag even if every generation of cars have lower Cd values.

=D> =D> =D>

By the way: our Cd.A best values are very very low (much less than a SUV, that is big but without aero devices). Is there someone who knows the Cd.A values of real Le Mans prototypes?

[rjsa]

I understand all that, I really just wanted to know where the meaningless number was being thrown, and now I got it. If you want my opinion, just get rid of the CD and Area reports. If someone wants to know their real CD, just figure out the project area and calculate it.

[LVDH]

You are right, the values are carry over from the full version but I will remove unnecessary stuff for the new MVRC edition which I will release soon. If you see anything else which should be kicked out just let me know. Removing stuff is easy.