February Test Thread

[kilcoo316]

some kind of air flow monitoring ??

What on earth is that going to tell them?

I'd be very surprised... no, I'd be shocked if their prediction tools (wind-tunnel and CFD) were qualitatively out. If that is the case - scratch 2009 for McLaren!


I think there is very little in the way of hard numbers can be measured from that with much accuracy.

[Conceptual]

I did speculate that it looked like a drastic test to understand an issue with the new car, possibly the wake of the front suspension. And someone else speculated it may be to test the wake of the adjustible front wing.

Lets just hope that Scarbs is nearby, and he gets to the bottom of this!

It seems as if he is the only one to ask the right questions...

[myurr]

I did speculate that it looked like a drastic test to understand an issue with the new car, possibly the wake of the front suspension. And someone else speculated it may be to test the wake of the adjustible front wing.

Lets just hope that Scarbs is nearby, and he gets to the bottom of this!

It seems as if he is the only one to ask the right questions...

To me it just looks like they've extended the idea from last season where they tested the front rim shields. I couldn't find any info or pictures in the quick 5 second search I did but I seem to remember them doing this on other parts at the front of the car last year as well.

I wouldn't read too much into it. They're probably just verifying certain interactions and subtleties to make sure their predictions are correct. It can't give that much away to the other teams otherwise they'd expend more effort in hiding it.

They weren't exactly struggling last year when they used it on the rim shields, so why would they be struggling now just as they've extended the idea? The wind tunnels, CFD and other simulations they do are not perfect and I'm sure it's the case that the more real world testing they can do the better.

[Conceptual]

I still think that Scott should sell some UV "invisible" water soluable solution that they can use instead of that green stuff... Regardless for what it is for.

[wesley123]

That isnt for monitoring airflow.

The green stuff flows up after the upper arms so that cant be it as the suspension arms arent allowed to produce downforce.

[PNSD]

A quick word.

I do believe the paint settles in high pressure areas...

If so, then it is obviously good to see it at the leading edge of the rear wing, and the endplates. Also around the sidepod inlets and the rear diffuser.

[i70q7m7ghw]

Why would teams wan't to copy anything if they suspect McLaren have problems because they are spraying green paint on their car? Sure sure let's copy a bad idea

Or maybe they do want to copy it because it just validates McLaren's wind tunnel results that the car is the fastest of all the '09 cars... oh wait... WE DONT KNOW... NEITHER DO THEY!

=D>

[kilcoo316]

That isnt for monitoring airflow.

The green stuff flows up after the upper arms so that cant be it as the suspension arms arent allowed to produce downforce.

Front wing wake.

[Scotracer]

That isnt for monitoring airflow.

The green stuff flows up after the upper arms so that cant be it as the suspension arms arent allowed to produce downforce.

And because they don't produce downforce means they have no airflow surrounding them?

Suspension components on these cars produce a considerable portion of the car's drag so to understand the flow characteristics is vital.

One problem I have with the method: Using this to find airflow is all well and good when you have a constant/steady state system as this dye/paint/stuff sticks to surfaces...but as soon as you have things changing (pitch/yaw/air velocity) the reasons will be completely nullified. Flow velocity is a critical factor in aerodynamics! And look at the range at Jerez: 100km/h to 300km/h. Hmm. The Reynolds number will constantly changing on these surfaces so the seperation points will be changing all the time.

Colour me sceptical.

[ISLAMATRON]

I was think along the same lines... and to that point I would think that straight line testing, like the teams conduct air airstrips would be much better accomodating to this type of testing.

[timbo]

The Reynolds number will constantly changing on these surfaces so the seperation points will be changing all the time.

Colour me sceptical.

Apparently they can monitor such changes using onboard camers - notice additional one at the rear of sidepod.
I actually like that idea of using paint, but I think the downside is that they can only see what happens on surfaces, but not how vortices interact in volume.

[ISLAMATRON]

The Reynolds number will constantly changing on these surfaces so the seperation points will be changing all the time.

Colour me sceptical.

Apparently they can monitor such changes using onboard camers - notice additional one at the rear of sidepod.
I actually like that idea of using paint, but I think the downside is that they can only see what happens on surfaces, but not how vortices interact in volume.

I havent done much wind tunnel testing... is that what they use the smoke for?

[djos]

A great result for the new RB5, 63 Laps and still the fastest '09 car* on only its it 2nd day on track! =D>

1. Sebastien Buemi Toro Rosso STR3 1.19:660 - 104 laps
2. Sebastian Vettel Red Bull RB5 1.22:177 +2.517 - 63 laps
3. Nico Hülkenberg Williams FW31 1.22:443 + 2.783 - 82 laps
4. Heikki Kovalainen McLaren MP4-24 1.22:634 + 2.974 66 laps
5. Nelson Piquet Jr Renault R29 1.23:313 + 3.653 - 35 laps

Renault still the slowest by 1.2 seconds.

*at Jerez

[vyselegend]

All this painting stuff reminded me of a post of Ciro from a long time ago:

This is an old software I saw several years ago, when it seemed cool, by Carnegie-Mellon, for "popups". Not in the league, but...

http://www.cs.uiuc.edu/homes/dhoiem/pro ... tware.html

A "little on thread", I posted eons ago something about pressure sensitive paint. Perhaps that's what the teams should use for "aero" comparisons...

VW new Beetle pressure coefficients at 50 m/s


Delta Wing, from 10 to 30 degrees (Quick Time required)


It is said that you can get 1.5 mbar precission and 0.5 seconds time lag.

Might be relevant here... Or not.

In case it is, it would make sense since other teams can't see any secret by just looking at the painting, but they have to bring the car back at the factory to analyse it... maybe that chassis will fly to England tonight and another one will be used tomorrow. Or I'm just wrong and it is possible to make the analyses on site.

[El Presidente]

My guess is that its PSP - Pressure Sensitive Paint, used to validate existing windtunnel and CFD work. Why do it outside rather than in the tunnel? Well do you want the tunnel to be out of action after every test while its getting cleaned?