About the Mercedes rear wing (as of China).

[vonk]

Here’s my conjecture about the principle of the Mercedes “Horn” (my term).



Of course it’s a 2-dimensional concept, and I know the real world facts are far from that. Nonetheless, one has to start somewhere. I’ve been reminded that an airfoil’s pressure distribution is constant with speed, and so the pressure ratio between inlet and outlet will always be constant. But does that hold for multi element “air boxes”? Then there are the 3-dimensional effects, such as the tip vortexes and the disturbed under-wing flow (hardly a “free stream”).

I wonder what the louvers in the end plates on the MGP W01 do, and what the cutouts in the end plates right behind the upper elements are for, and why the outlet slots on the back of the upper element are strangely curved and placed so high. All in all, the flow near the rearward face of the upper element seams sufficiently complex to have an influence on the pressure at the outlet slots. Also how hard must the slots blow to stall (separate the boundary layer) the upper element if the boundary layer is laminar (doubtful) or turbulent. Thus, my question in this post:

viewtopic.php?f=6&t=8429&p=164989#p164989

Comments appreciated.

[cornermarker]

Sorry to borrow your illustration, but don't forget the inevitable vortex:



Do we have any shots of the outlets?

Kelpster

[JohnsonsEvilTwin]

Excuse my limited knowledge but where is the actual inlet?

[autogyro]

I do not think this makes sense of the 'horn'.
IMO Merc were simply trying the rest of the wing that is to be used with a new engine cover to include the high pressure ducting.
IMO this horn is part of a test program to gather data.

[JohnsonsEvilTwin]

Autogyro +1

This is what I was thinking, as it needs to be fed from an inlet which, so far as I can tell does not exist...yet.
Does anyone know if the merc was faster in a straight line as a result of it?

[zgred]

Excuse my limited knowledge but where is the actual inlet?

Not the best picture but quite visible inlets.

[autogyro]

Possibly but the picture is to small.
If you mean the two on the top of the side pods, there is no obvious continuation of the ducting to the rear wing.
These could also be for data gathering.

[zgred]

...
If you mean the two on the top of the side pods, there is no obvious continuation of the ducting to the rear wing.

I meant inlets are in the lower element of the rear wing. In accordance with the vonk idea on the matter.

Unfortunately picture is really small.

[autogyro]

Nowhere near enough to blow the slot effectively.
Boundary layer recovery maybe but more likely a test of the wing elements prior to adding the engine cover ducting.

[zgred]

Possibly it was just a test before Spain and data collection as You mentioned autogyro.


Wires for sensors?

But on the other hand Ross Brawn said they had passive system, so it was doing something more than simply collecting data - otherwise they would not use it in the race.

In its bid to improve its car’s competitiveness, Mercedes also tried out a rear wing-stalling device at the last round in China as teams try to copy the F-duct concept pioneered by McLaren which helps increase straight-line speeds.

Brawn says the wing system it trialled last week was only an interim solution, however, and hopes the full F-duct will be ready to be incorporated onto the W01 early into the European season.

[autogyro]

Would make sense that Ross tried the blown rear wing without the blow ducting to confirm the aero balance on the current chassis.
R and D on the wing aero is always on going.
If this was the case there should be at least 7 tenths in Barcelona just on the blowing and extra strait line speed.

[gambler]

The adjustability of it makes me wonder if it has to do with changing the downforce point foward or rearward to compensate for fuel burn off.

[PlatinumZealot]

Nowhere near enough to blow the slot effectively.
Boundary layer recovery maybe but more likely a test of the wing elements prior to adding the engine cover ducting.

Then again, maybe it's not to blow the slot. A small disruption to the flow behind the wing might be enough to trigger the stalling. ?

[Timstr]

Close-up of the entry slits.

[autogyro]

Nice pic. I still think this one is to help the boudery layer stay attached at higher angles of attack and the intake slots are far to small to blow stall the wing.
Does anyone know if the Merc rear wing moves backwards on it mountings by much at higher speeds?