W06 Influenced CFD Study

[turbof1]

I dissasembled the pieces of my drawings. Chuckdanny is prepping a CAD render, so hopefully I can help him in that regard by opening up details:


Marked with red are the very tiny vortex generators. Be sure not to miss those!


Images for references on where everything is positioned:


(I made a small mistake with that last image; the upper strake on the outside of the endplate was one from 2014. I forgot to hide that one when generating the image ).

Some notes however on the underbody strakes:

(on the left is the new set, on the right the old one)
At the moment I am not sure of the shape of the new set. I can confirm Mercedes removed one of the strakes, and the outer one is that short, but all else is quite open. I currently lack any good images; however once we have a good shot I'll update that.

[chuckdanny]

THanks turbof1! I think i'm not too far off so i can continue

[theWPTformula]

THanks turbof1! I think i'm not too far off so i can continue

http://oi58.tinypic.com/2lmql4p.jpg

Wow, this looks fantastic! What software are you using?

[PlatinumZealot]

THanks turbof1! I think i'm not too far off so i can continue

http://oi58.tinypic.com/2lmql4p.jpg

That looks like Solidworks... Looking good.
My advice is to get some wing profiles cross sections to use for your lofts if you haven't already. CFD is pretty much hit or miss if the fundamentals aren't there.

[ArgyrisB]

THanks turbof1! I think i'm not too far off so i can continue

http://oi58.tinypic.com/2lmql4p.jpg

wow that seems spot on, great work! can't wait for some CFD.

How did you make that, insert images and work on them or from scratch?

[chuckdanny]

Thnaks!

Yes it's solidworks, more options in catia but ergonomy of swx is unbeatable.
I will try Platinumzealot but i will never get the trailing edges right because it's too thin a resolution.
@Argyris : just a front view in swx but hopefully(to talk like a racing driver) there are many images of this wing already, kind of guess work in areas (just seen that the flaps are not right seen from above) but i try to have something easy to adjust if needs be.

[turbof1]

It's not an easy wing, but you aren't completely out of luck. Outside the new arched sections and the v section, basically little to nothing has changed to the wing, meaning you can base yourself on pictures before the Malaysian change.

If you need a particular part of the wing from a specific angle, don't hesitate to ask!

[George-Jung]

Holy mother of Jezus!!! This is exactly the reason why I joined this forum!
You can not find this anywhere else, keep it up boys =D>

[bhall II]

While those CAD drawings look great - and they really do; probably the best I've seen here - the likelihood that any CFD analysis of them will produce results in any way representative of reality is virtually nil, meaning the likelihood that the results will be very misleading is almost assured. The various interactions that define the overall system are just too complex for us mere mortals, especially in this area, one in which the transient conditions are of much higher importance than steady-state.

Unless all components are considered over a range of various conditions, like the "brake ducts" that actually serve to shield the wing from turbulent flow around the wheel, the system will not behave as intended.



Accuracy even demands the inclusion of areas that may not be initially apparent...

To take a simple example, if one creates a blockage downstream of the front-wing, then this will reduce the velocity of the airflow over the front-wing, reducing the downforce it generates. Conversely, if one accelerates the airflow downstream of the front-wing, then this will also accelerate the airflow over the front-wing, increasing the downforce it generates.

There are also more subtle examples of this type of aerodynamic spookiness. Back in 2006, the change to 2.4 litre V8 engines in Formula 1 triggered the proliferation of so-called flow conditioners atop the nose of the chassis. These appendages re-aligned the upper-body airflow in a manner which reduced the rate of airflow over the front-wing, but increased it over the rear-wing. Recall that the downforce generated by a wing is proportional to both the speed of the airflow over it, and the angle-of-attack of the wing. Thus, Formula 1 teams wishing to compensate for the loss of engine power, could reduce the drag generated by the rear wing for a given level of downforce, by reducing the angle-of-attack, but increasing the airflow over it. (See 2006 Formula 1 Review, Mark Hughes, Autosport December 14th/21st).

I just think that should be noted is all. I'm sure the pictures will be pretty. But, that's all they'll be.

[turbof1]

We don't have to draw conclusions out of it. It's just nice to take up such a project once and a while. We will not be able to fully simulate the real life counterpart, but we might learn something out of it.

I however also underline to be careful with interpreting cfd images. There's a great amount of work behind them and we really have to appreciate that. I just want to warn everybody not to take cfd as facts, but simply to discuss at heart about! we don't often get to do this though, so we have to appreciate the oppertunity.

[chuckdanny]

Still i think that cfd can give a better picture of what this arche accomplish for example, i mean i trust more cfd which embed a lot of knowledge from highly intelligent people over 200 years. We could trust our intuitiveness but it falls short sometimes.

I thought that thoses arches where creating two conter-rotating vortices going around the front wheel, more so because they repeal each other and the 1st basic test case i did show exactly this, i'm happy

But they are no streamwise louvers in this case, would the picture change or will the vortices reinforce ?

[turbof1]

Still i think that cfd can give a better picture of what this arche accomplish for example, i mean i trust more cfd which embed a lot of knowledge from highly intelligent people over 200 years. We could trust our intuitiveness but it falls short sometimes.

I thought that thoses arches where creating two conter-rotating vortices going around the front wheel, more so because they repeal each other and the 1st basic test case i did show exactly this, i'm happy

But they are no streamwise louvers in this case, would the picture change or will the vortices reinforce ?

You mean the underbody strakes? Yes I think the picture will change quite a bit.

My initial idea was what you said, but Bhall explained to me this couldn't be the idea behind the update. Although it's very much possible that those vortices are being created, something as an unintended byproduct.

I think for now going towards the interaction with the rotating wheel is important to have a better idea. As Bhall also stressed at, such a wheel has to be turned because this basically changes the blockage (which I assume isn't such an issue, since I believe you already ran cfd with turned wheels). We might still be off its real life counterpart, but it should put us in a better position.

However, just keep working at ease towards a full model!

[bhall II]

Due to the time constraints imposed by the racing schedule, Formula 1 teams routinely partner with academic institutions to dig deeper into the physics and answer fundamental questions concerning the airflow around the car. An example of this has been the collaboration between Toyota F1 and Stanford University. The Stanford group was asked to investigate the flow around an isolated tire to identify the dynamics of the flow structure in the wake, determine if computer simulations match experimental measurements and understand under which circumstances the flow becomes asymmetrical with respect to a vertical plane that cut the tire in half. In spite of the broad knowledge regarding the aerodynamics of bluff bodies, the flow distortion introduced by the tire rotation, the interactions between the rubber and the ground under load, the effect of the air captured and then released by the brake system, and, in general the uncertainties related to the unknown geometry of the tire, pose tremendous challenges to a complete understanding.

Even by itself, let alone with everything else, flow around a rotating wheel is ridiculously complex.

[chuckdanny]

Well as i say i will never get the numbers that's pretty obvious but the basic flow seems right, the 2 counter rotating vortices trailing the tire in your video of a Large eddy simulation are there in my numerical steady state swimming pool.

[bhall II]

Yeah, and you'd see roughly the same flow if the tires were sideways...



I guess my view of the matter is just different than the prevailing one around here. And that's fair enough, I suppose.