Williams FW41 Mercedes

[ME4ME]

That's where I disagree.

With the reliability that is now expected from these PU's, I truly believe that the design/shape/situation of the PU is 100% based upon reliability, and the chassis is designed around it. I feel that weight distribution, mass-centroid axis, CoG, and transitional torsion to be the most important things when integrating the chassis to the engine. Paddy knows the way Merc handles these items, and I would expect that they are FULLY built into the FW41.

I think it's quite naive to think that Mercedes will not design the PU as they deem fit with their very own car in mind. It's the exact thing Ron Dennis argued was required for a team to win the championship. Williams simply do not have the ability to adapt the PU to their needs.

[Zynerji]

The rules have changed since then, and if you MUST only use 3 engines for the entire season, there shall be ZERO compromise that prevents that from happening.

[Ashwinv16]

Obviously Ferrari's Sidepod covering flow conditioners seems to be mainstream solution although it is important to remember that both Toro-Rosso and Mercedes raised their upper front wishbone to counteract the same problem(But it also required changing the suspension geometry for stability) so it will be interesting to see how many more teams employ Ferrari's solution to the larger front Tyre wake or will there be teams employing Toro-Rosso's version.

What's this about sidepods being a front tyre wake solution? Could you explain this?

It's actually a really complex to explain. So for the 2017 season the size of the barge boards and the front tyres were increased. The width of the car thus was increased as well however the teams were still only allowed just about the same distance from the Sidepod entrance to the front wheel centre line. So the barge boards now allowed for more air to be easily moved around the Sidepods however teams noticed that the increase in front tyre width greatly increased the wake from the front wheels(Front tyre wake greatly increases drag) which severely effected the performance of the Bargeboards. To compound the problem the Front wings, which is also important in controlling the front tyre wake, were also made more angular so the air coming from the front wing flaps especially the leading edges completely changed so now teams had to figure out which parts of tyre wakes they wanted to focus on(Upper, inner or outer).
If you notice Red Bull focused on their front wing, changing it considerably compared to others in order to better manage the Y250 vortex thus focusing on the inner tyre wake.

Mercedes and Toro-Rosso effectively placed their upper front wishbone much higher so that the flow from the front wing and leading edges now provides a similar effect to how it was in 2016.(The ratio in distance between the front wing flaps to the suspension stayed the same. (Not exactly its much more complex than that but this is a simple explanation))

The Force India placed it's front suspension system as forward as it possibly can thus giving it the same effect as Mercedes and Toro-Rosso (Also that fractured platypus beak-like nose). Other teams also did their own thing but these are the ones that actually worked.(Mclaren also focused on their front wing similar to Red Bull Thanks to Peter Promodeau, but you get the idea)

Also notice that these solutions meant that they used the full extent allowed for their Barge Boards. Ferrari however had a different idea and the idea that gave them the best car Aerodynamically in 2017. They found out that by moving their sidepods backwards and covering it up by placing a very efficient flow conditioner(which now the two launch cars have copied)(The angled sidepods was the intended design but teams could technically just move their sidepods backwards and place flow conditioners in front of it to make up for the extra space and just to make sure these flow conditioners go through, the mandatory side impact structures were placed in it (See my post on Hass VF-18 thread for more about the side impact crash structures) they could better deal with the front tyre wake.

Notice that, because of the placement of their flow conditioners the brage board doues not use the entire extent of what the regulations allows cause the flow conditioners and the cover underneath them takes car of that.

Also the deflectors like the Ferrari focus on moving the air around the Sidepods (Unlike Haas's version which almost solely focuses on pushing the air above the Sidepods and relying on creating a "curtain" of vortices to minimise the effect of front tyre wake downstream while the large plate-like deflectors in the Williams acts like the "Curtain" by itself. It's also why the Haas has a blown axle while the Williams doesn't need it(At least until the more downforce heavy circuits like Barcelona where Drag does not matter that much)*.

I am very curious about these "vortex curtains". What do you mean by this? For the record, Ferrari had (and probably will have this year as well) blown axles last year, this doesn't seem to be correlated with deflector design.

I did mention in my post that Williams will still bring the Blown axle to testing for sure but again some teams need it and some teams don't which brings this to the side pod deflectors. These deflectors not only help channel the air from the barge boards and the front part of the car down stream, they are also responsible for making this air stay within the car helping rear airflow efficiency and performance. These purposely induce vortices so that the flow will be more attached to the sidepods thus reducing boundary layer separation from the airflow over the sidepods. The vortices induced by the plate like one in the launch car and in last years Ferrari is smaller compared to what Haas wanted to do (See my post on Haas VF-18 thread). The tyre wake coming from the outer wall mostly will come in contact with these deflectors(With the Help of the Blown Axle and the Front wing) and these deflectors will basically diminish the wake.

Now these plate-like deflectors basically covers up the side till the level that the regulations allow like a curtain(Which is why the vorticies generated by them is much less) while Haas's version if you notice doesn't(Like last year's Mercedes and Williams and Sauber)They have gaps in each flap and they are angled upwards(Or towards the back in the Mercedes). So while the air flowing around the deflectors in the Williams will be conditioned to stick with the sidepods, Haas,last year's Mercedes and Williams aimed at accelerating the flow above (or Around) the sidepods so that the large number of vortices(Again like a Curtain covering up the sidepod but behind the Intake entrance, i used curtain as a simple description thus the two quotation marks) are generated by this which then helps to attach the airlfow over the sidepods at the same time minimising the Front tyre wake. It's all about whether you want to reduce the front tyre wakes effect down stream(in the case of the plate-like deflectors) or condition the Airflow from the deflector so that the front tyre wake passes through the deflectors but is changed to improve performance and reduce drag, in the case of the Haas. Remember some teams like Force India did not even bother with this too much cause their car preferred more of this wake from the tyres as it probably worked well with their complex Barge Boards. (Even after all this work not all of the air actually sticks with the sidepods but Most does, teams that can condition the air to stay within the car are the ones that are more successful.) (Best example will be Red Bull, cause the moment they focused on the use of the deflectors and the airflow around, above and under the sidepods in general their performance immediately went up)

The 2017 Diffuser in the Ferrari was probably the most flawed concept as they tried to make a low Drag diffuser to produce more downforce which added more drag unfortunately which did work at low speed circuits but affected it's High speed cornering (Not Medium speed, high speed like Silverstone, the car was fast in Malaysia)

Are you sure we are ready to point fingers at one part of the aero package and calling it "the most flawed concept"?

Maybe not but I remember Ferrari testing their own car with a similar diffuser to Red Bull and Mercedes and the 2018 Williams launch car, it's just based on what I know/read/learned.

Moreover, I’m intrigued to see how far Ferrari take it, a year on in its evolution; it’s one thing coming to a solution new but another to have a year’s worth of experience and data. Like with other things of this nature (ebd, for example) you imagine the initial innovator has the opportunity to always be one step ahead in the development.

Always was, and always will be like that.

Not all Teams will need to do what Ferrari did with their Sidepod flow conditioners, can expect Mercedes, Toro-Rosso and Force India to stick with the normal version, unless they decided to change their concept.

[tomazy]

So what is Williams hiding with all that black paint? Maybe an extreme undercut to the point that the car almost has double floor? Lets compare to the 2017 Ferrari:







This is all my speculation, we need to see the real car to confirm or dissmis this.
Also, my paint skils

[roon]

So what is Williams hiding with all that black paint? Maybe an extreme undercut to the point that the car almost has double floor?

Looks like the sidepod joins the floor normally.

Brightened image

[tomazy]

I am still not convinced, there is alot of the top of the floor wisible just under the air intake.

[Vanja #66]

tomazy, you might be right mate.



That's not an undercut, that's a full cut...

Ashwinv16, I'll read and answer your post carefully tomorrow morning. Cheers!

[Unc1eM0nty]

Very bad news for Williams fans, Gary Anderson has declared car to be good.

The day you can tell how a chassis will perform from what it looks like is the day I'll stop posting. Mercedes chassis was declared light years ahead last year when unveiled, but the simple looking Redbull was by far the better chassis in the end.

Isn't that what happens on this forum all the time?? In this very thread it has been mentioned that the new Williams isn't as "slippery" and will have more downforce than previous modern Williams cars, with that all suggested from just a handful of launch pictures

Haha, I couldn't agree more

[DinkLv]

Regarding the side deflectors of the sidepods, I don’t think they are as complex as someone thinks to be able to accelerate airflow or deliberately create a vortex as a ‘fence’. The have multiple elements because they are large plates and you need to ensure that the air stays attached to it under yaw. If you don’t have slits there will be separation on the outside and isn’t good for aero mapping. In an awful lot of cases we should take aero mapping and yaw condition into account.

In my opinion the deflectors are used to prevent reflux of the expelled tyre wake. As the coke bottle contracts air is induced into between the bodywork and rear wheel. On the other hand the air accelerates between the initial sidepod undercut and the deflector, as the space gets arrow while you need to keep the mass-flow rate. It has lower static pressure, which is perpendicular to the incoming flow, than the low-speed tyre wake, which has a much higher static pressure. As the static pressure differential is perpendicular to the incoming flow it would push the tyre wake back to the initial sidepod undercut, where the deflector is placed. If you successfully prevent the reflux then it will be much less likely to have such a reflux around the latter bodywork. So that’s why we have deflectors placed exactly here and have different kinds of slits to prevent separation on the surface in corners. Or it’s just because the regulations limit the size of deflectors and the teams would expand the deflectors all the way across the length of bodywork if not limited.

[Vanja #66]

It's actually a really complex to explain. So for the 2017 season the size of the barge boards and the front tyres were increased. The width of the car thus was increased as well however the teams were still only allowed just about the same distance from the Sidepod entrance to the front wheel centre line. So the barge boards now allowed for more air to be easily moved around the Sidepods however teams noticed that the increase in front tyre width greatly increased the wake from the front wheels(Front tyre wake greatly increases drag) which severely effected the performance of the Bargeboards. To compound the problem the Front wings, which is also important in controlling the front tyre wake, were also made more angular so the air coming from the front wing flaps especially the leading edges completely changed so now teams had to figure out which parts of tyre wakes they wanted to focus on(Upper, inner or outer).

Ok, so you are saying that front tyre wake is being regulated with front wing, barge boards and (later) front suspension. That's not false by any means. However, let's take a thought experiment on what's going on with front tyre wake. Front tyre is bigger, so is the wake. Wake is turbulent airflow, caused by boundary layer separation, caused by (in our case) abrupt change in geometry of the wall (outer surface of the tyre) and wall movement (rotation of the tyre in respect to the airflow, and this is only true for real fluids, not ideal fluids). As turbulent airflow, wake is a low pressure zone and with bigger wake - bigger the pressure difference. The air, like all other substances, materials and living things, will always go to the path of least resistance - low pressure areas are that path. Therefore, with the tyre you will have the outer portion of the air (the one that's on the boundary between turbulent and laminar airflow outside of boundary layer) go towards this turbulent wake after they pass the tyre itself. We can call it suction, sort of. Now, I know you are familiar with all of this, but bear with me, I'm not patronizing you.

Now, with a single isolated tyre in free stream you'd theoretically have symmetrical suction on both sides. With the front tyre, you have barge boards and bodywork downstream, so the air passing between the chassis and front tyre is directed outward. All of this would happen even if we don't have the front wing. This would happen even if we don't have barge boards, all that's needed is another wall downstream (bodywork in our case) causing a high pressure zone directing the air away from it.

Front wings and side pod leading edges were made angular for aesthetic reasons for 2017, not aerodynamic. Teams haven't changed their basic front wing philosophy one iota. As you can see on the picture bellow, comparing SF-70H and SF-16H, flaps are at almost the same angle on these cars, the only thing that's changed is leading edge sweep angle. We still have Y250 vortex, we still have aggressive outwash endplates, differences between teams are subtle differences for their own specific aerodynamic philosophy.

If you notice Red Bull focused on their front wing, changing it considerably compared to others in order to better manage the Y250 vortex thus focusing on the inner tyre wake.
http://e0.365dm.com/17/02/16-9/20/skysp ... 0227090910

This is what was tested on RB13 in Abu Dhabi, since it wasn't raced we can assume it was 2018 development part. This is just a subtle modification, focusing on the initial height of Y250.

Mercedes and Toro-Rosso effectively placed their upper front wishbone much higher so that the flow from the front wing and leading edges now provides a similar effect to how it was in 2016.(The ratio in distance between the front wing flaps to the suspension stayed the same. (Not exactly its much more complex than that but this is a simple explanation))
https://cdn-5.motorsport.com/images/mgl ... -str12.jpg
The Force India placed it's front suspension system as forward as it possibly can thus giving it the same effect as Mercedes and Toro-Rosso (Also that fractured platypus beak-like nose). Other teams also did their own thing but these are the ones that actually worked.(Mclaren also focused on their front wing similar to Red Bull Thanks to Peter Promodeau, but you get the idea)
https://cdn-9.motorsport.com/images/mgl ... detail.jpg

Merc and STR placed their suspension up, because they were focused on lower part of the air stream between front tyre and chassis - no doubt about it. Again, these are subtle differences for minor aero improvements in relation to their desired philosophy, but this is what F1 is all about. The thing is, this is not simply for front tyre wake, this is for management of airflow with high energy and getting it towards the floor and the back of the car with as little energy loss as possible. Front tyre wake is only one of the elements that induce energy loss, but it's naturally pushed outwards and you can make it go out sooner or later, depending on what you want to do with the rest of the airflow.

Compare W07 and W08 bellow, in the front they are not so different, so the basic philosophy is still the same for these two cars. Camera pods on the nose are lifted as high up, suspension geometry is much the same...

Also notice that these solutions meant that they used the full extent allowed for their Barge Boards. Ferrari however had a different idea and the idea that gave them the best car Aerodynamically in 2017. They found out that by moving their sidepods backwards and covering it up by placing a very efficient flow conditioner(which now the two launch cars have copied)(The angled sidepods was the intended design but teams could technically just move their sidepods backwards and place flow conditioners in front of it to make up for the extra space and just to make sure these flow conditioners go through, the mandatory side impact structures were placed in it (See my post on Hass VF-18 thread for more about the side impact crash structures) they could better deal with the front tyre wake.
https://gas2.org/wp-content/uploads/201 ... bourne.jpg
Notice that, because of the placement of their flow conditioners the brage board doues not use the entire extent of what the regulations allows cause the flow conditioners and the cover underneath them takes car of that.

And we arrive at the critical moment. If I understand you correctly, you assume that Ferrari (and now Williams with FW41 as well) lifted the side pod leading edges to avoid collecting turbulent tyre wake into the radiator intake? To continue this discussion, I'd like to be sure I understood you correctly. I'll return to the rest of your post later, when you confirm your thoughts.

Cheers!

[tomazy]

ESPN has a nice rotating model of the car where you can batter see the shape of the sidepods and the huge undercut.

http://www.espn.com/f1/story/_/id/22454 ... s-new-fw41

[f1316]

ESPN has a nice rotating model of the car where you can batter see the shape of the sidepods and the huge undercut.

http://www.espn.com/f1/story/_/id/22454 ... s-new-fw41

That’s perfect, thanks.

So as you say, it’s a massive undercut at the front, but it’s also not a double floor as it doesn’t continue along the length of the sidepod.

[mmred]

ESPN has a nice rotating model of the car where you can batter see the shape of the sidepods and the huge undercut.

http://www.espn.com/f1/story/_/id/22454 ... s-new-fw41

That’s perfect, thanks.

So as you say, it’s a massive undercut at the front, but it’s also not a double floor as it doesn’t continue along the length of the sidepod.

the ferrari aero solution combined with mercedes therrmo efficiency really did wonders ( what the official team with an even better non client pu will do is soon to come ) but let s say
the ferrari aero solution had a massive effect even on has



100% adoption seems no brain

[tomazy]

The small frontal area of FW41 sidepods is what is so diffirent to last year Ferrari car and Hass. Granted, Hass sidepods are a bit narrower at the top, but below the inlets, there is a big diffirence.

[mmred]

The small frontal area of FW41 sidepods is what is so diffirent to last year Ferrari car and Hass. Granted, Hass sidepods are a bit narrower at the top, but below the inlets, there is a big diffirence.

https://image.ibb.co/dngkMS/2018.jpg

https://image.ibb.co/fjQ9Fn/20181.jpg

the difference is the radiator volume
the aero efficiency of mercedes radiators was already better
thats why if ferrari and nnew has improved williams cut everythin
of course now it s up to ferrari to compare ( but radiators are the limiits )