Mercedes AMG F1 W03

[Pup]

...I would also agree with the far more logical suggestion that the ducts exposed when the DRS is active must be exits, not intakes, and the air is blowing across the rear wing main plane to stall it and reduce drag even further than the DRS alone...

The exposed ducts are most likely the switch, with the major flow happening elsewhere. Think of the old f-ducts - the wing covering and uncovering the opening is analogous to the driver covering and uncovering the old fluidic switch control with his hand.

[hardingfv32]

The exposed ducts are most likely the switch, with the major flow happening elsewhere.

Have you noted any possible sources for the primary flow? I can't say I have noted anything unusual.

Brian

[Pup]

My guess is that the intake is the secondary inlet behind the main air intake, and the flow is going through the duct that connects to the beam wing. I think the beam wing is what's being blown, since it's outside the rules limiting the rear wing itself. Where the pilot flow from the wing goes, I'm not sure, but it could be hidden under or within the main duct. Someone mentioned two ducts were visible? I haven't been paying close enough attention myself. Anyway, I'm guessing that there's a fluidic switch, similar to before, under the engine cover that directs the main flow either through the duct to the beam wing or simply out the engine cover exit.

[hardingfv32]

Minimum inside radius. The wing would be unpractically thick if the closed section folded in on itself to create a slot/cavity.

Is this what you are talking about: 'Furthermore, no part of this section in contact
with the external air stream may have a local concave radius of curvature smaller than 100mm.'

So you think the since the duct is using outside air the it's inside shape would be controlled by the 100mm restriction. Is that correct?

I don't think that is an issue if the channel is fed by a flat walled channel. The flow is turned in the side support structure to align with the wing axis. Not ideal, but workable.

Brian

[hardingfv32]

My guess is that the intake is the secondary inlet behind the main air intake, and the flow is going through the duct that connects to the beam wing.

That is a sound proposal. So now we need a little knowledge about the drag levels of the main and beam wings to determine where we get the most ban for the buck. I see what I can find.

May I assume that drag reduction of the diffuser is not in the running?

Brian

[Pup]

Is this what you are talking about: 'Furthermore, no part of this section in contact with the external air stream may have a local concave radius of curvature smaller than 100mm.'

So you think the since the duct is using outside air the it's inside shape would be controlled by the 100mm restriction. Is that correct?

I don't think that is an issue if the channel is fed by a flat walled channel. The flow is turned in the side support structure to align with the wing axis. Not ideal, but workable.

It's true that you can get the air into the wing and still meet the rules, by bringing it in through the side like you say. It's getting the air out of the wing that's the problem.

Take a string and tie the ends together to make a circle. That's your closed section as required by the rules. Now try to arrange the string so that you have a wing section like you need to have a slot. You see that you need to fold the string back on itself to create the cavity and the slot. Now adjust it so that you have no inside curve with less than a 100mm radius. You'll see that any wing with a slot would have to be at least 20cm thick, which is impractical.

[PlatinumZealot]

....

[Tatsu333]

May I assume that drag reduction of the diffuser is not in the running?

Brian

From what I recall, the drag from the diffuser vs. the amount of downforce it produces is negligible, so I think that would be unlikely.

Stalling the beam wing is a possibility, but the logic of that considering what we know (or think we know!) of duct locations seems unlikely. Think of it this way:

If the source intake is ahead of the beam wing, and air travels through the duct we've seen in the crash structure, through the beam wing, and up the endplates to the holes exposed by the DRS, then when those holes are opened (the "fluidic switch" idea), one would think there would be actually be LESS blowing from a slot in the beam wing because resistance would be taken away further along the path. This would make the blowing effect stronger when DRS is not enabled, which would be the opposite of what you would want.

Conversely, if the source intake is the holes exposed by the DRS, then what is the point of the duct in the crash structure?

There may be another possibility, if we're talking about the main effect being on the beam wing: using the blown air to add flow/velocity to the underside of the beam wing (by orienting a slot to exit parallel to the bottom surface rather than perpendicular, as you would to stall it), thereby increasing the downforce produced by the beam wing when the DRS is not active. When the DRS is active, and the holes open and an alternate path for the air to escape out those holes becomes available, reducing the effect. If that's what's going on, a shot of the beam wing from behind/slightly below might show the required slot(s) on the underside of the wing.

Again, I'm not an aerodynamicist by any stretch of the imagination, so I don't know if that's even feasible, but it seems like a possibility to me...

EDIT: Just realized - wouldn't that be an application of the Coanda effect?

[Tatsu333]

...I would also agree with the far more logical suggestion that the ducts exposed when the DRS is active must be exits, not intakes, and the air is blowing across the rear wing main plane to stall it and reduce drag even further than the DRS alone...

The exposed ducts are most likely the switch, with the major flow happening elsewhere. Think of the old f-ducts - the wing covering and uncovering the opening is analogous to the driver covering and uncovering the old fluidic switch control with his hand.

Remember that in the old F-duct system, that "switch" operated ahead of where you would want the stall effect, and was open by default. With the hole uncovered, the effect was lessened because the air escaped into the cockpit, while with the hole covered, more air travelled further rearward to blow the rear wing.

Given that the rear wing holes are covered by default (I.E. when DRS is not active), if they are indeed the "switch", then I think we may be looking for an effect that we want lessened, not increased, when DRS is active as those holes release pressure or reduce resistance to flow coming from the duct in the crash structure (with a source somewhere ahead of that). An effect that meets that criteria is what I suggested above - blowing to increase downforce of the beam wing.

[dren]

There is no need for a fluidic switch because the covers on the rear wing endplates are the switches. The fluidic switch was used because it wasn't a "physical" switch which circumvented the rules two years ago.

How much flow and at what pressure is needed to stall a wing? The old F-ducts were pretty narrow. Mercedes routed theirs through the endplates before. This isn't anything new to them. They also had a small opening to route the air. Their passive system had small openings as well. I don't think we need as much flow as we are thinking.

I don't think we can throw Scarb's idea out the window so quickly.

[hardingfv32]

Remember that in the old F-duct system, that "switch" operated ahead of where you would want the stall effect, and was open by default. With the hole uncovered, the effect was lessened because the air escaped into the cockpit, while with the hole covered, more air travelled further rearward to blow the rear wing.

No, the signal circuit when flowing can switch the primary flow either on or off depending on its design or layout.

What kind of flow can we expect from the exposed DRS slot? Is this a really high pressure area still or has the louvers changed things?

Brian

[aduka11]

Still no one seems to have clue what giant hole in the nose is for ?

Driver cooling as specified in the rules.

Brian

I've seen openings on noses for driver cooling trough whole decade...But this one is much bigger than all i've seen so far....

Btw in prevous pages of this thread someone pointed out that there were small ducts on front wing.

Why isnt this soultion not possible?

[thevlack]

http://www.youtube.com/watch?v=7l9QjD9X ... r_embedded

[skgoa]

After all, apart from quali, the DRS can only be used if they manage to catch up on a car ahead.

So? Every bit counts, especially when it means you can set the car up with more dowforce because you know you can shed more drag when you need to.

OK - having seen the shot of the front of the chassis (where the nose connects), I would agree there is no ducting from the RW to the nose, so the DRS-activated blown front-wing is almost certainly a myth. (Not saying that a separate, passive blown front wing is out of the question, though...)

With that in mind, I would also agree with the far more logical suggestion that the ducts exposed when the DRS is active must be exits, not intakes, and the air is blowing across the rear wing main plane to stall it and reduce drag even further than the DRS alone. My only thought is that the air would be hard-pressed to affect the centre of the main plane, because the oncoming (external) air would deflect the ducted flow pretty strongly. How effective that would be, I have no idea, but I guess every little bit helps!

As suggested by Raptor22, this would only create a bigger front/rear imbalance, making the DRS less useful on corner exit during qualifying, for example, but perhaps they've found the trade-off in top speed on the straights to be worth that compromise. It would allow them to run a more aggressive main plane on the rear wing, which would help in the slow to mid-speed corners, where you wouldn't be using DRS anyway, and might help with rear tire wear in the race.

The intakes could be anywhere allowed by the rules, really, but it seems clear from previous images that there is a duct inside the rear crash structure that the wing mounts to that must channel the air into the beam wing and up the endplates (the reverse of the diagram from Scarbs). This suggests a fairly obvious intake location ahead of that - either up around the roll hoop, or integrated into the sidepod intakes. For that matter, Red Bull's ducts in the lower sidepod sides (the much-vaunted "tunnels") would probably work too - they are apparently "well advanced" in developing their own version after all.

I agree. Then again, this is exactly what I have been saying for days.

I don't always gloat but when I do, I'm obnoxious about it.

[skgoa]

Let me understand this:
The armchair aero guys are saying its more beneficial to stall a DRS activated wing, thereby shedding more downforce and creating a bigger front rear aero imbalance....?

fricking incredible logic

No. What we are saying is that stalling the RW mainplane is creating even more of a DRS benefit, while stalling the FW would upset the whole aero of the car. The FW doesn't generate that much drag anyways. Oh and balance doesn't really matter as much on the straight.

I just reviewed 3.10, Bodywork behind the rear wheel centre line, and do not see why the main element can not have a stalling slot. Now that is not to say I was reading it correctly. Can anyone point to some wording that might precludes a slot?

Brian

Minimum inside radius. The wing would be unpractically thick if the closed section folded in on itself to create a slot/cavity.

Isn't there a senctence about "closed surface" as well?

I've seen openings on noses for driver cooling trough whole decade...But this one is much bigger than all i've seen so far....

Nope, thats an optical illusion due to the thinner nose. The size of the hole is regulated.