Mercedes-AMG F1 W10 EQ Power+

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turbof1
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Re: Mercedes-AMG F1 W10 EQ Power+

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GPR -A wrote:
27 Feb 2019, 14:39
turbof1 wrote:
27 Feb 2019, 11:49
GPR -A wrote:
27 Feb 2019, 07:38
We have good reasons to accept your explanation, versus the conviction of those who have created this with the help of hundreds of professional folks working on multi-million (if not billion) dollar facilities. I truly believe that they have completely ignored such a critical possibility like the one you have explained. Yep.
You forget this is testing. Mercedes is testing. IMO, what Vanja said is 100% right and frankly it's nothing out of the ordinary either. They are pushing the wing to its limit and try to see just with how much they can get away with. That's perfectly normal, as this wing could have been right on the edge in their simulations and now they try to verify that on track.
What I find amusing, is the statements that I have highlighted. How do you define the boundary conditions for them. They are very vague and have arrived without any scientific methods to it (probably based on vague theoretical understandings), whereas it might actually be a desired thing for Mercedes! Who knows. It's not that they can't get an understanding of the flow structures, without running it on track. Now what is the limit? How do we know? The purpose of tightening the sidepod package, is to feed as much high velocity air as possible and in as much uninterrupted manner as possible to the wing. In that way, it might even be desired.

I find it difficult to understand that, if someone like @Vanja can derive a conclusion that Mercedes have pushed the wing over the limt, killing the diffuser and floor performance AND it is bad and it can't provide mid-corner-behavior-predictability, how ignorant could Mercedes folks be, that a thing which so easy for an average normal forum member to understand, is something they haven't despite possessing multi-million resources.

It's a good thing to present the thoughts on what one sees through the car pictures and present the guess work in more humble manner, than to outrightly conclude that it is bad without having done any practical study of that guess work.
Vanja actually has the (distinctively relevant) education to back for it, so I wouldn't so carelessly suggest "vague boundary conditions". We have an article from last week where we already discussed the wing:
https://www.f1technical.net/development ... h-flow-viz
We concluded here even though the seperation that is definitely happening is perfectly acceptable. However, now, the flow is distinctively much more separated. This is not in an ambigious zone of "is this just below, right on or slightly over the limit". No here the separation is of that order it leads to downforce loss in all probability.

Let's not turn this into a toxic discussion about who has the right to back up his claims. I'll end it at that Vanja's original message:
Mercedes have pushed their wing over the limit. And quite badly so, separation of about a third of this length (chord-wise) would be acceptable, this is not. This is also killing diffuser and floor performance, just a bit but enough. Can't imagine this wing would provide the car with required mid-corner-behavior-predictability.
is correct. There is no implication they did anything necessarily grossely wrong. Again, Mercedes is trying what the limits are on these new wings. They are clearly looking for it, else they would not have bothered with the flow viz! Just because they overstep it here, which they did factually, does not mean this was a mistake. This is very useful data for Mercedes to develop on.

Again, that's the end of the discussion regarding credentials. If anybody disagrees, then they should be specific in their counter arguments and tell us what the flow viz pattern tells otherwise. Just trying to bring doubt and discredit is not leading to a fruitful conversation.
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mantikos
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Re: Mercedes-AMG F1 W10 EQ Power+

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Vanja #66 wrote:
27 Feb 2019, 09:09
GPR -A wrote:
27 Feb 2019, 07:38
We have good reasons to accept your explanation, versus the conviction of those who have created this with the help of hundreds of professional folks working on multi-million (if not billion) dollar facilities. I truly believe that they have completely ignored such a critical possibility like the one you have explained. Yep.
Good for ya laddie!

Serious question:

Wouldn't adding serrations to the trailing edge of the main plane of the wing help push the seperation bubble further out? As in, would the flow stay attached longer to the second element if Mercedes reintroduces the serrated trailing edge solution they ran from a few years ago?

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Vanja #66
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Re: Mercedes-AMG F1 W10 EQ Power+

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mantikos wrote:
27 Feb 2019, 16:04
Serious question:

Wouldn't adding serrations to the trailing edge of the main plane of the wing help push the seperation bubble further out? As in, would the flow stay attached longer to the second element if Mercedes reintroduces the serrated trailing edge solution they ran from a few years ago?
Sure it would, laddie! :D This isn't a big problem, RW is always working on knife edge, teams probably have at least 5 different solutions to choose from to solve RW trailing edge separation. Serrated edge is my favourite, btw.
And they call it a stall. A STALL!

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NoDivergence
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Re: Mercedes-AMG F1 W10 EQ Power+

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I've had designs that at 45-50 deg flap angle have separated worse than than flowvis pic and still had more downforce than the 40 deg position. Drag and efficiency is worse, but I agree that it is far too simplistic to right off the bat say that they lost downforce here. What I remember very clearly is a diffuser in ground effect paper that shows flowvis and right where everyone thinks that it's separating like crazy and going spanwise, it's actually experimentally making the most downforce like that. Depending on the flap leading edge radius, the higher AOA, can get more initial suction. That combined with the higher pressure on the upper surface can compensate or even be better overall in downforce for the wing system. It can also affect wake bursting characteristics of the main element which you won't see from flowvis at all since it is downstream

PhillipM
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Re: Mercedes-AMG F1 W10 EQ Power+

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PlatinumZealot wrote:
27 Feb 2019, 14:03
I have a few cad projects designing suspension and i cant see why you say this.. You sure u wanna make that claim?


The springs are not just there doing nothing they will push back and steer the hub (assuming the psuh rod is mounted on the hub and off-set). The hub doesn't care if its a tie rod or pushrod. Even the article you linked alluded to that... Its just regular shmegular maths /geometry /kinetics that dictate it..
Anyway let's put this topic aside for separate thread.
Certain I do, yes, I've dozens of kinematics setups sat here myself.

It's very, very easy - in a bump, does the tyre steering angle deviate away from the steering wheel position commanded by the driver, compared to a traditional setup?
Answer, no. The steering force may change, depending on your longitudinal position.
But then steering force changes over bumps anyway. And the Merc setup is slightly rearward so could actually make the loads more linear over kerbs, etc, by countering the rearward force vector when the tyre initially climbs them.

Just_a_fan
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Re: Mercedes-AMG F1 W10 EQ Power+

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Leon wrote:
27 Feb 2019, 14:55
Before / After
https://i.imgur.com/7Y22Hby.jpg
The "after" picture appears to have the original front wing fitted. There is no cut out of the endplate as on the new wing.

Did Mercedes run a mixed package of original wing with new bodywork/bits? It would be sensible to see whether the original wing would work.
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miguelalvesreis
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Re: Mercedes-AMG F1 W10 EQ Power+

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Yes they did

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turbof1
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Re: Mercedes-AMG F1 W10 EQ Power+

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NoDivergence wrote:
27 Feb 2019, 16:25
I've had designs that at 45-50 deg flap angle have separated worse than than flowvis pic and still had more downforce than the 40 deg position. Drag and efficiency is worse, but I agree that it is far too simplistic to right off the bat say that they lost downforce here. What I remember very clearly is a diffuser in ground effect paper that shows flowvis and right where everyone thinks that it's separating like crazy and going spanwise, it's actually experimentally making the most downforce like that. Depending on the flap leading edge radius, the higher AOA, can get more initial suction. That combined with the higher pressure on the upper surface can compensate or even be better overall in downforce for the wing system. It can also affect wake bursting characteristics of the main element which you won't see from flowvis at all since it is downstream
I saw the same paper, and yes that is correct what you state. I believe it was one from Willem Toet?

Do mind the rear wing is not a diffuser. We can't simply take a diffuser and apply what we learn from it on a rear wing, as the flow towards the rear wing is entirely different (flow in ground effect vs more relative free stream flow). Also, I believe (not sure and not bothered to look back) Vanja stated a bit of separation can indeed be beneficial for peak downforce, which is what we also said in our article last week. Since that picture, mercedes brought this rear wing and separation is a lot worse.

Maybe we should look for different pictures of rear wing covered in flow viz so we can compare and reach a mutual understanding what looks good flow and what's not. That would be much more productive. These are last year's wings:
Image
Image

This is this year's wing in week 1:
Image

Second week:
Image
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Just_a_fan
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Re: Mercedes-AMG F1 W10 EQ Power+

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NoDivergence wrote:
27 Feb 2019, 16:25
I've had designs that at 45-50 deg flap angle have separated worse than than flowvis pic and still had more downforce than the 40 deg position. Drag and efficiency is worse, but I agree that it is far too simplistic to right off the bat say that they lost downforce here. What I remember very clearly is a diffuser in ground effect paper that shows flowvis and right where everyone thinks that it's separating like crazy and going spanwise, it's actually experimentally making the most downforce like that. Depending on the flap leading edge radius, the higher AOA, can get more initial suction. That combined with the higher pressure on the upper surface can compensate or even be better overall in downforce for the wing system. It can also affect wake bursting characteristics of the main element which you won't see from flowvis at all since it is downstream
It might be considered useful to run the wing such that it is "draggy but high downforce" as with your 45deg flap example. This gives good performance in the corners but then, when the DRS is opened, the drag disappears and you still get the straight line speed you want.
If you are more fortunate than others, build a larger table not a taller fence.

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Vanja #66
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Re: Mercedes-AMG F1 W10 EQ Power+

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NoDivergence wrote:
27 Feb 2019, 16:25
I've had designs that at 45-50 deg flap angle have separated worse than than flowvis pic and still had more downforce than the 40 deg position. Drag and efficiency is worse, but I agree that it is far too simplistic to right off the bat say that they lost downforce here.
Indeed, it varies. I've had designs where 70 deg flap has separation for about 1/10th chrod length (so less than Merc) gives lower downforce than 65 deg (where there was just a bit of separation in the middle of the wing) and also lower drag. How come lower drag? Well, due to a loss of pressure difference, caused by separation, which propagates upstream a bit. At 75 deg it was game over, there was separation 10mm after the slot.

It varies and depends on a lot of things, aerofoils especially. There were a lot of situations before, where teams've had problems with less separation than Merc had, namely Sauber last year. Also, as turbof1 showed us, Merc never utilised this much sepparation before. For the record, I haven't seen either Ferrari, Red Bull or McLaren display this much sepration. But I might have missed it...

NoDivergence wrote:
27 Feb 2019, 16:25
What I remember very clearly is a diffuser in ground effect paper that shows flowvis and right where everyone thinks that it's separating like crazy and going spanwise, it's actually experimentally making the most downforce like that.
Diffuser can have separation in the middle of it and still work. I haven't ever seen a diffuser TE separation show performance increase. I imagine teams now adding 3 and even 4 wee flaps above diffuser TE means they don't want it to seperate there. Ever.

NoDivergence wrote:
27 Feb 2019, 16:25
Depending on the flap leading edge radius, the higher AOA, can get more initial suction. That combined with the higher pressure on the upper surface can compensate or even be better overall in downforce for the wing system. It can also affect wake bursting characteristics of the main element which you won't see from flowvis at all since it is downstream
It can also cause serious problems when DRS shuts and flow doesn't re-attach. :wink:
Last edited by Vanja #66 on 27 Feb 2019, 18:14, edited 1 time in total.
And they call it a stall. A STALL!

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GPR-A
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Re: Mercedes-AMG F1 W10 EQ Power+

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I would leave it to experts to spot the difference and help us understand.

W10 and SF71H (Click to enlarge)

Image

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Vanja #66
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Re: Mercedes-AMG F1 W10 EQ Power+

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That's W09 actually and neither show nearly as much as this wing level on W10 does. Just what do you think separation is, exactly? Can you show it on these pictures be drawing circles over it? I'm honestly starting to think we aren't talking about the same thing here.
And they call it a stall. A STALL!

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TRICKLE69
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Re: Mercedes-AMG F1 W10 EQ Power+

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There are way to many bs opinions in these threads. I come to look at pictures of the cars and the discussions about the technical aspects of them. I personally could care less about the stupid bickering over who is correct or not when discussing the different aspects of the cars. You want to bicker back and forth do so privately so we do not have to read the bs. Thanks.
IT IS WHAT IT IS

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Mr.G
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Re: Mercedes-AMG F1 W10 EQ Power+

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TRICKLE69 wrote:
27 Feb 2019, 18:30
There are way to many bs opinions in these threads. I come to look at pictures of the cars and the discussions about the technical aspects of them. I personally could care less about the stupid bickering over who is correct or not when discussing the different aspects of the cars. You want to bicker back and forth do so privately so we do not have to read the bs. Thanks.
Actually, I would like to see it. I'm no expert in airo and learning lot of from the discussion...
Art without engineering is dreaming. Engineering without art is calculating. Steven K. Roberts

Just_a_fan
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Re: Mercedes-AMG F1 W10 EQ Power+

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TRICKLE69 - you are correct to a degree, however, if someone is saying "X" and someone else says the samething is "Y", it's useful to figure out which is correct. Sometimes this does come down to a thrash-out between those people - oftentimes, the outcome is that people are actually agreeing but using dissimilar terms and so causing confusion.

So long as the to-and-fro is kept civil - and preferably without people quoting and requoting excessive lengths of each others posts - then it's all beneficial to us all in the end.

The over-quoting is the thing that kills it for me. I often read threads on a phone and having to page through the same paragraphs quoted and requoted and then requoted again, all in their entirety, kills the thread dead.
If you are more fortunate than others, build a larger table not a taller fence.