Mercedes W13

[f1jcw]

Thats not sounding good, sounds like they have gone in the wrong direction.

Yes, if it's correct, but is it? Where did Paulo Filisetti the technical journalist get this info? These would have to have been missed by Mercedes aero's in their wind tunnel, which does do yaw presumably.

I agree, its seems highly unlikely that detached flows from the upper surface of the car went unnoticed in simulations and wind tunnel. In my opinion it is way more likely that the car is set to run very low, but they cannot do that because of porpoising. I think that in Mercedes case rising the car height causes a loss of downforce higher than in other cars.

There is always the possibility that they stuck too much to previous years concepts and miss out some new opportunities that the new regulations offer, but it is too early to say. I guess we will have to wait at least until Imola/Barcelona to know who was right.

Plus if it is disastrious as they say, I'd presume they'd be even lower down the grid as it would sound like a complete dud

[Stu]

Thats not sounding good, sounds like they have gone in the wrong direction.

Yes, if it's correct, but is it? Where did Paulo Filisetti the technical journalist get this info? These would have to have been missed by Mercedes aero's in their wind tunnel, which does do yaw presumably.

I agree, its seems highly unlikely that detached flows from the upper surface of the car went unnoticed in simulations and wind tunnel. In my opinion it is way more likely that the car is set to run very low, but they cannot do that because of porpoising. I think that in Mercedes case rising the car height causes a loss of downforce higher than in other cars.

There is always the possibility that they stuck too much to previous years concepts and miss out some new opportunities that the new regulations offer, but it is too early to say. I guess we will have to wait at least until Imola/Barcelona to know who was right.

Whether true or not, there is some scope for this being plausible.
a) - Mercedes had the least amount of wind-tunnel time at the beginning of last season.
b) - Mercedes had the most ground to make up to catch Red Bull at the beginning of last season (along with AMR they were more heavily affected by the floor changes).
c) - No matter what they do in the tunnel, flow detachment is difficult to spot (unless every square mm of model is covered in pressure sensors.
d) - Wind tunnel testing is limited to 180km/h, although I believe that they are allowed to model higher speeds in CFD. CFD runs are also limited.
e) - The airflow changes with speed.

As I say, whether true or not, it is plausible.

[zibby43]

[pimpwerx]

Upper bodywork affecting W13's underfloor aerodynamics
In a way, it is a strange phenomenon that can be explained by the fact that the upper bodywork of the W13 dramatically affects the aerodynamics underneath the car.

The result is that with certain combinations of speed, lateral acceleration and ride height, the car suddenly loses downforce due to the fact that the airflow passing on top of the upper bodywork suddenly detaches from it, especially in the area between the sidepods and the engine cover.

In a nutshell, we can say that the airstream detaches at this level and does not continue towards the rear end.

Furthermore, the shape of the sidepods generates a sort of spillage through the floor sides, reducing the efficiency of the floor with sudden pressure changes underneath.

Mercedes set to bring updates for their car to Imola
This is not a phenomenon that can be managed with set-up changes. As far as we know, a first aero overhaul of the W13's current concept is expected for the fourth round of the 2022 season at Imola, and its final step will be introduced two races later at Barcelona.

Though several observers suggested that Mercedes' power unit was inferior to those of Ferrari and Red Bull, the team does not appear too concerned by this, as their data suggests that they were not able to deploy all their engine's performance due to their car's lack of stability.

https://racingnews365.com/why-mercedes- ... th-the-w13

Dubious source. Plus, we haven't seen Merc going heavy on flowvis on their sidepods. Seems to be the part of the car they're least-concerned about, really. Contrast that with McLaren who drenched the whole side of the car in flowvis. If flow was detaching, I imagine we'd have seen them applying liberal amounts of flowvis to those sidepods.

[PlatinumZealot]

Yes, if it's correct, but is it? Where did Paulo Filisetti the technical journalist get this info? These would have to have been missed by Mercedes aero's in their wind tunnel, which does do yaw presumably.

I agree, its seems highly unlikely that detached flows from the upper surface of the car went unnoticed in simulations and wind tunnel. In my opinion it is way more likely that the car is set to run very low, but they cannot do that because of porpoising. I think that in Mercedes case rising the car height causes a loss of downforce higher than in other cars.

There is always the possibility that they stuck too much to previous years concepts and miss out some new opportunities that the new regulations offer, but it is too early to say. I guess we will have to wait at least until Imola/Barcelona to know who was right.

Whether true or not, there is some scope for this being plausible.
a) - Mercedes had the least amount of wind-tunnel time at the beginning of last season.
b) - Mercedes had the most ground to make up to catch Red Bull at the beginning of last season (along with AMR they were more heavily affected by the floor changes).
c) - No matter what they do in the tunnel, flow detachment is difficult to spot (unless every square mm of model is covered in pressure sensors.
d) - Wind tunnel testing is limited to 180km/h, although I believe that they are allowed to model higher speeds in CFD. CFD runs are also limited.
e) - The airflow changes with speed.

As I say, whether true or not, it is plausible.

180kph is fast enough for a 60% scaled car!
If the wind is going 180kph and the model car is 2.7 meters long... The wind would be passing a full scale car at 300kph. That is more than enough methinks.

[Just_a_fan]

Upper bodywork affecting W13's underfloor aerodynamics
In a way, it is a strange phenomenon that can be explained by the fact that the upper bodywork of the W13 dramatically affects the aerodynamics underneath the car.

The result is that with certain combinations of speed, lateral acceleration and ride height, the car suddenly loses downforce due to the fact that the airflow passing on top of the upper bodywork suddenly detaches from it, especially in the area between the sidepods and the engine cover.

In a nutshell, we can say that the airstream detaches at this level and does not continue towards the rear end.

Furthermore, the shape of the sidepods generates a sort of spillage through the floor sides, reducing the efficiency of the floor with sudden pressure changes underneath.

Mercedes set to bring updates for their car to Imola
This is not a phenomenon that can be managed with set-up changes. As far as we know, a first aero overhaul of the W13's current concept is expected for the fourth round of the 2022 season at Imola, and its final step will be introduced two races later at Barcelona.

Though several observers suggested that Mercedes' power unit was inferior to those of Ferrari and Red Bull, the team does not appear too concerned by this, as their data suggests that they were not able to deploy all their engine's performance due to their car's lack of stability.

https://racingnews365.com/why-mercedes- ... th-the-w13

Dubious source. Plus, we haven't seen Merc going heavy on flowvis on their sidepods. Seems to be the part of the car they're least-concerned about, really. Contrast that with McLaren who drenched the whole side of the car in flowvis. If flow was detaching, I imagine we'd have seen them applying liberal amounts of flowvis to those sidepods.

Exactly so. I think it's a click bait story.

[SiLo]

Why would the flow become detached from the sidepod/engine cover area and not all other cars that have similar surfaces at similar angles?

[Shakeman]

I don't think it would take until Imola to create a whole new body shell, would it? Merc can 'simply' build a new bigger body shell which has a shape less prone to flow detachment, they can have fresh air under it if they need.

The story could be true as airflow of the diffuser will affect floor performance and I was arguing earlier that the floor had a far too 'peaky' performance. This could be a reasonable explanation as to what's happening and analogous to the McLaren blocker issue.

[vorticism]

Why would the flow become detached from the sidepod/engine cover area and not all other cars that have similar surfaces at similar angles?

That antler thing is no simple shape, perhaps it's not operating as intended.

[Just_a_fan]

Why would the flow become detached from the sidepod/engine cover area and not all other cars that have similar surfaces at similar angles?

That antler thing is no simple shape, perhaps it's not operating as intended.

The car is not performing because they are having to compromise the underfloor downforce by lifting the car. This is to reduce the porpoising issue. The car suffered porpoising with the previous bodywork that didn't have the SIS shroud, ergo, the shroud is unlikely to be the core issue.

Quite why the flow over the top of the sidepods should suddenly detach when the ride height drops a few millimetres is not explained in that click bait article, of course. Why? Because it's a click bait article.

[Just_a_fan]

The cut down rear wing now fitted with a gurney tab and the Petronas logo has been reapplied so that it is a full logo.

[vorticism]

That antler thing is no simple shape, perhaps it's not operating as intended.

The car is not performing because they are having to compromise the underfloor downforce by lifting the car. This is to reduce the porpoising issue. The car suffered porpoising with the previous bodywork that didn't have the SIS shroud, ergo, the shroud is unlikely to be the core issue.

Quite why the flow over the top of the sidepods should suddenly detach when the ride height drops a few millimetres is not explained in that click bait article, of course. Why? Because it's a click bait article.

Wasn't a response to the article (didn't read) was a response to the question I quoted. They claimed the car has similar shapes and surfaces to the other cars, which is inaccurate. Flow attachment to the sidepods incl. the antlers, and perfectness thereof, is unknown to us.

[RZS10]

The cut down rear wing now fitted with a gurney tab and the Petronas logo has been reapplied so that it is a full logo.

I'm sure it's a completely different wing, or rather DRS flap


edit: Russell is using the cut down version.
edit2: comparison from sky

[PlatinumZealot]

You know F1 is lame when you see two pages about a cut down rear wing flap.

God I miss the days of radical cars and cheap, ugly downforce.

[Just_a_fan]

The cut down rear wing now fitted with a gurney tab and the Petronas logo has been reapplied so that it is a full logo.

I'm sure it's a completely different wing, or rather DRS flap
https://i.imgur.com/E4NtXbn.png

edit: Russell is using the cut down version.

It's certainly very different and looks ever less like a "cut and shut" job tack side.