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Williams FW41 (text & illustration by tw) February 16, 2018

On February 16, 2018, Williams' new machine [FW 41] was released.
The chief engineer of this machine is Paddy Row and the chief designer is Ed Wood.
See the photo of the machine, F1 Tushin.
I will write my opinion from the overview of the car body.

The front nose has the same standard shape as last year, and there is a nose hole that extracts the air current from the nose lower surface to the upper surface.
The nose hole may play a role of reducing the growth of the boundary layer from the bottom of the nose to its back.
This is similar to the boundary layer mitigation slit of the wind tunnel experiment equipment.

Since the front wing is black, its shape is not well understood, but this also looks like a standard design.

Last year's Mercedes had raised the aerodynamic efficiency by raising the upper arm of the front suspension higher than the wheel.
I am paying attention to how many teams will follow it this year, but [FW41] is the position to connect to the interior of the wheel as before.

Therefore, the angle at which the upper and lower wishbones come down from the monocoque is strong.
This is a design with more emphasis on aerodynamic efficiency than front roll center.
The tie rods are placed in the middle of the upper and lower arms and are dynamically safe. But a little air resistance increases.

The connection position of the monocoque side of the front push rod is slightly lower than the top face of the monocoque.
Therefore, it can be inferred that the pitch controller is laid out on the upper side of the locker.


Canards which grows obliquely backward from the side of monocoque stand out.
However, in the rear, black upper border wings are growing. (This is also connected to the vertical vanes at both ends before the side pod.)
It looks like it is black and hides in plain, but in fact it seems very high aerodynamic effect.

The rear view mirror has a trendy shape, rectifying by suppressing the air current bounced by the front wing.

The rear part of the side protector to which [Halo] is connected seems wondering whether the air current does not peel off here because the narrowing to the inside is abrupt.
However, the recent F1 side protector rear design has this tendency.
This may be due to the reason that it is desired to increase the pressure by lowering the flow velocity on the side pod upper surface in the vicinity.

The tip of the upper side of the side pod does not squeeze the air current upwards, it does not cause lift.
Obviously this is influenced by last year's Ferrari.

Subduction of the upper side of the side pod to the rear is very large.
This may be close to the concept of Red Bull last year.

The area of the shark fin was regulated from this season.
[FW41] has "cut shark fin" of the largest area permitted within its provision.
This is because we want to alleviate even a bit of cornering that the airflow overcomes the engine cowl and generates harmful vortices.
On the front of the fin, behind the camera on the roll bar, there is a horizontal "dish" with a small width.
This will act as a shark fin garney flap.

The upper arm angle of the rear suspension is nearly horizontal.
This is because I want to raise the lower arm to increase the efficiency of the rear diffuser.

The stay of the rear wing is a swan neck. Like last year's Ferrari, [FW41] has two stays.

When I look at the whole machine, it looks like a new model that reconsidered the concept from the foundation, not the evolutionary type since last year, and it seems like it is.
The driver is Sergei Syltokin (22 years old), who will debut this year with Reims Stolle (19) from last year and F1 this year. It is a young pair with little Grand Prix experience.
I am worried whether they will be able to draw out the potential of [FW 41] sufficiently and will be able to proceed with development in the right direction.
However, it is safe for Robert Kubica who signed up as a reserve driver to contribute to development with a simulator.


It is a burning work, but I will explain it with illustrations.
Yellow green is Canard,Yellow is upper border wing,Orange is a vertical vane,Pink is "halo"
I designed it from the imagination that I can not see in the picture.


Although this illustration is not drawn, in order to satisfy the flat bottom regulation, there should be an under border plate with an area larger than the shape projected under Canard and upper border wing. (Otherwise you can not go.)

Canard returns the course of the airflow that the front wing bounced back to the horizontal, but the aerodynamic contribution rate is not as high as it looks.
The shape of the under borders below it will be important.
In the past, the person of Toyota F1 team testified.
"If you put a small bread on the top of the side pod, there is little harm, but if you paste a piece of hair on the bottom of the car body, the aerodynamic performance will be destroyed."

However, as Canard and the Upper Border Wing work in concert, I do not absolutely deny Canards unconditionally.

In the upper row I think that the angle of attack of the upper border wing is more effective than Canard.
The bottom of the upper border wing will be in the high pressure zone, supplying more air current to the bottom of the car body, and should enhance the ground effect.
The aerodynamic effect of the ground effect is the most effective means to create the greatest downforce with the least air resistance.



(Updated on March 21, 2018.)

I was able to find a new device of [FW41] from the test running picture.
For the shape, see F1-Gate.com.
It has a Y-shaped, long front and rear fin on the horizontal part of the top of the engine cowl.
The effect of this can be interpreted as a large gurney flap against the swirling flow in the transverse direction during cornering.

This idea is a new idea that can be appreciated with a more aggressive approach than the traditional simple vertical shark fin.
Last year's Shark fin reduced the adverse effect of the turbulent air current overcoming the engine cowl during cornering on the rear wing.
However, this year's Y-shaped fins will give a course of swirling to the airflow trying to overcome it, and will exert a literally large garney flap-like effect.

This year, as explained at the top of this page, the area of the shark fin was restricted.
Among the strict regulations of this year, you can see the intention to supply high quality airflow to the rear wing at the cornering.

Other teams have already verified this in CFDs and wind tunnels.
If it is effective, it seems to be a popular device of this year.

The length in the front-rear direction of the horizontal part of the induction pod apex of [FW41] is much longer than the layout of the drawing I drew.
This means that the wheelbase of FW 41 is clearly longer than my drawing (3300 mm).
And the front-rear position of the monocoque which became freely somewhat may be close to the front wheel axle.

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