Mclaren Mercedes MP4-25

[f1rules]

it would have been nice, if we had a professional photographer, that would take pictures during most cars were out(same time), on the straight just before the braking point. With all the water standing, it would have given us an idea of the effectiveness of the diffusers, looking at the wake

[Raptor22]

....or they're simply measuring tyre wear and temperature...

[Mr.G]

Hi All,

Whad do you think about this idea, is it possible? Sorry I do not go trough all 66 pages

[newbie]

....or they're simply measuring tyre wear and temperature...

nope..

[Richard]

a little example here:

Thanks Ringo, I need that to educate the young grads at work!

[Raptor22]

Hi All,

Whad do you think about this idea, is it possible? Sorry I do not go trough all 66 pages

yes this has been discussed here already and the general consensus is that this is what some forum members think they are doing, myself included.

[Confused_Andy]

....or they're simply measuring tyre wear and temperature...

nope..

you have no evidence to prove otherwise, what a useless post.

[Shaddock]

....or they're simply measuring tyre wear and temperature...

nope..

you have no evidence to prove otherwise, what a useless post.

Tyre temp is measured via a small IR sensor pointed at the wheel/tyre, this device measures air pressure behind the front wheels.

[Tbox]

....or they're simply measuring tyre wear and temperature...

nope..

you have no evidence to prove otherwise, what a useless post.

If you can explain how they're measuring tyre wear and temperature using pitot tubes, go right ahead.

[Shaddock]

I wonder if they will mount it further back on the car as well?

[Mr.G]

Raptor22 - thanks, I'm proud to myself to discover it by my own you now how I mean that

[SZ]

some of the explanations here for that wake array have been simply rediculous. thanks for the laughs!!!

As some have suggested, it is a pitot array for measuring the front wheel wake...possibly THE most important characteristic of an F1 car as it's position and behavior has a knock-on effect on floor and diffuser performance.

Thank God someone's thinking - it's just a bloody wake rake, used in aero testing all the time. You use these in a tunnel to interrogate flow, e.g. in F1 you'd use it to measure performance against CFD. Flow around a rotating wheel is highly unstable and very, very difficult to get right in CFD. The interactions between wheel and front wind endplate are very significant also (a few good papers on this floating out) so all in all there's a lot going on in this region and it's important to understand what's what.

They'll probably have chosen a few steady state positions (straight ahead, full lock turning, etc) and are simply mapping the flow behind the front wheel to see what's what. It's possible they're also very smart and are using it to look at transient behaviours e.g. as the car moves from straight ahead to yaw, as the front wheel turns, etc.

You can pick up the steady state positions in a wind tunnel no problem but there are always scaling effects.

You can't pick up the transient stuff in a wind tunnel as you can't reposition a model quickly enough (not at >=50% scale).

It's a pain in the ass having a full grid of pitot tubes as that's quite intrusive and the channel count is very high, much easier to manufacture a single row and then just traverse that. They're probably sampling very, very quickly.

Given that the rake alone takes an age to make, I don't think this is a sign of desperation from McLaren, they'd have looked at building this a long time ago as getting some decent data out of a slow day or similar.

n smikle, you do it in a wind tunnel as easily as you would on track either with a similar rake, usually with one fixed to the tunnel. The device that you traverse doesn't necessarily have to be a pitot tube, it can be any device used to interrogate flow. This is pretty standard in aero testing for anything.

***
Tyre temperature is measured with infra red pyrometers generally and there's only three of them used (inner, middle, outer). How people might think these sensors - that run far wide of the width of the tyre - are measure tyre temperature is beyond me.

***
Mr G, Raptor 22, that cannot be what McLaren's doing with their rear wing. The pipe losses in such a duct would be huge. That alone gives me a clue as to what they might be up to, which is potentially far more sinister than what you've presented here.

Think about it.

***
Whoever pulled up that flow viz pic of last year's car, the distribution of paint looks normal. It'll blow off where the air is faster and it's fastest on the underside of a big wing in clean flow. I'd suggest they've applied it everywhere evenly.

I'd also suggest that that pic was taken when McLaren had no idea what the car was doing and were getting desperate, or you'd have no need to do the entire rear end.

[Pup]

Mr G, Raptor 22, that cannot be what McLaren's doing with their rear wing. The pipe losses in such a duct would be huge. That alone gives me a clue as to what they might be up to, which is potentially far more sinister than what you've presented here.

Think about it.

Thinking. Got nothing, and I dare day I have a pretty sinister view. I'd think that even with the loss you'd still come out ahead pumping air across the wing, considering the considerable pressure difference between the intake and the rear of the wing. No? It seems like a logical development of the 'scoop' they were so proud of last year.

Well, actually, I'd considered that they were somehow using the whole arrangement to alter the shape of the wing, but the BLCS concept seemed far more likely.

Whoever pulled up that flow viz pic of last year's car, the distribution of paint looks normal. It'll blow off where the air is faster and it's fastest on the underside of a big wing in clean flow. I'd suggest they've applied it everywhere evenly.

I'd also suggest that that pic was taken when McLaren had no idea what the car was doing and were getting desperate, or you'd have no need to do the entire rear end.

If you're talking about this...



It's this year's car. (Unfortunately?)

[SZ]

It's a start but rather than muse over what high pressure/high quality air could do over the pressure side of the wing, a more sinister thought concerns what a disruptive quality of air could do under it. Which alone doesn't reveal the most sinister thought of such a system... let's see who gets there first .

The flow viz paint distribution is normal but I'd be saddened if it was this year's car. They really need to shoot whoever's doing their viz mixture.

[Pup]

We may be on the same page already - adding a stream of air to the underside of the wing to keep the boundary layer attached (which could possibly be controlled to a degree). But I'm not sure I'd call that air 'disruptive'. Still thinking.