Well looks like it's been confirmed, the weird vent on the rear of the MP4-25 is not just to vent air, it's an elaborate BLCS.

http://www.formula1.com/news/technical/2010/0/720.html

On the McLaren above the driver's helmet, the air inlet is separated into 2 sections, intake for the engine, and an air channel for what was speculated to be for the oil cooler, but is in fact for the gearbox radiator.

Rewind back to 2009, McLaren was struggling big time with high speed aero at the beginning of the year. They could not understand why their rear wing at high speeds was losing tons of downforce. Turns out, the way the original front wing was designed, the airflow was interfering with the rear wing in such a way that at a certain speed (basically high speed corners) the rear wing stalled and just lost downforce. In testing, they threw on the 2008 wing to try and figure out what was going on.

This was finally fixed by a new aero package for the German Grand Prix, where Lewis described the car as "switching on". McLaren had changed the airflow from the front wing to not interfere with the rear wing. Simple as that.

One of the effects of the stall was that aerodynamic drag was reduced along with downforce. McLaren decided to exploit this by blowing the proper higher pressure air around the wing, and is able to tune the speed in which the air was able to reattached better, thus creating a low drag zone at high speeds, basically on straights. This concept is used in glider planes for drag reduction.

Some aircrafts use this system (blown flap) to lower the stall speed of the wing so it can take off at lower speeds. This system allows for higher wing angles to be used without stalling. Basically, there's a point in the wing's angle of attack where it suddenly loses downforce and stalls (and creates a huge level of drag). By blowing high pressure air, you can increase the wing angle without stalling, thus creating more lift, or in a F1 car's case, downforce.

The MP4-25 has several access panels on the rear shark fin, which is speculated to be adjustable tuning devices to vary the pressure exiting the vent. This system should allow McLaren to tune the BCLS for each track, so it can get higher downforce (more wing angle) for the corners, but without the drag penalty on the straights, resulting in better fuel economy (a huge plus this year) as well as higher trap speeds.

Pretty cool stuff!

That's pretty sweet.. Thanks for the detailed info.

It's so indepth, so much more to downforce than what you'd expect.

I really like the neat aero features McLaren comes up with.








Found this random pic, funny !!
Its true through, McLaren always has so much instruments attached to their car.


like what the hell are these haha

Originally posted by ryanallan
I really like the neat aero features McLaren comes up with.



like what the hell are these haha

Those are sectored Pitot units, they measure the air pressure at each sector. My guess it they are trying to figure out where the eddies are strongest, as to view the turbulence path of the air.

That's fairly crazy that F1 would go that far for data analysis

Air Flow Detectors? Maybe to help with setup of this BLCS.. who knows, but if it helps them take the WCC this year, more power to them!

EDIT: Rick beat me to it!

thanks for making me look stupid in your quote

Originally posted by ryanallan


thanks for making me look stupid in your quote

A question was asked, he answered it. Keep your tears out of this thread.

wow your so cool

Originally posted by ryanallan
wow your so cool

Looks like I posted another quote that makes you look stupid, sorry

Back on topic:

Are any of you really that surprised that F1 is going this far? When times come down to hundreds of a second, you'd think that you'd do anything to get an edge.

not surprised one bit, I'd expect it to be honest.
all very cool

This is one of the greatest geek battles of F1. For perhaps the first time, some are daring to declare that Computational Fluid Dynamics (CFD), which is theory (with maybe some empiricism) and supercomputers, has advanced to the point where it can simulate reality better than wind tunnels.

Wind tunnels are also simulations of reality, but they're reactive - you put something into the wind tunnel and measure the results (and watch smoke trails) to see how it behaved. First, of course, you actually have to build that something, or at least a scale replica of it. Maybe that's quick with drafting stations tied in to rapid prototyping machines, but still it involves a lot of physical effort in addition to computation. It becomes more challenging when you want to evaluate different effects, such as travelling behind other cars (air disruption and hot exhaust), side winds, etc.

CFD could be more predictive than reactive, in that you could design more based on how you want something to behave. However, critics are saying that even with some of the most advanced supercomputers, the programming and computation time required is very similar to what you need to conduct wind tunnel testing! And of course you have to worry about bugs and errors, either in the actual software or input of the design and testing parameters.

Simulations, either wind tunnel or computer, are still a long way from being able to model all aspects of reality, so there is not yet a replacement for testing. All the measurement gear hanging off the cars and all the laps run in a frenzied attempt to gather data points to compare to the wind tunnel and CFD results! Soon the work gets even harder as they try to equate practice, qualifying, and race data with design changes. Not to forget that you still need a driver that can make the car do what the design is supposed to permit!

It's like the Wright brothers in 1903 - you can't be sure how well that thing's going to fly until you try to put it in the air - except that F1 cars go into combat on that first flight. Less than two weeks and we'll start finding out!

Until this is solved:

http://en.wikipedia.org/wiki/Navier..._and_smoothness

Wind Tunnel > CFD.

It's impossible to predict turbulance right now, so anything past the front wing in a simulation is completely irrelevant.