Mercedes W13

[OO7]

I saw this light and initially thought it was glowing hot metal because that has been seen on cars before and appeared to coincide with sparking. However, I think it is only usually seen at night races. I can't imagine the metal getting hot enough to glow so brightly on a sunny day as this Sunday was. I also noticed it on multiple laps down the front straight and it could be seen all the way down to turn 3. I don't think glowing metal would stay that hot for that long. For example, I'm pretty sure glowing brakes lose their glow pretty quickly even through low speed corners.

Could you provide a screen capture of those laps, excluding the one in which Alonso was overtaken?

[Mchamilton]

4 pages debating whether the car has a sensor on it or not jesus

[AR3-GP]

4 pages debating whether the car has a sensor on it or not jesus

Somebody needs to tweet the MercedesF1 twitter page and put us out of our misery...

[Hoffman900]

They’re optical slip angle sensors have been commercially available from Datron and Correvit for twenty years now. I knew of FSAE and fast (deep pocket) amateurs who had them in the mid 2000s.

This isn’t new at all. Here is a white paper on how to use the Correvit ones:
https://www.yumpu.com/en/document/read/ ... sys-datron

If memory serves me right, the Datron ones were like $10k usd each in like 2007.

Unlike much cheaper laser ride height sensors, the optical sensors can measure yaw, slip, velocity, and ride height.

[MattWellsyWells]

I saw this light and initially thought it was glowing hot metal because that has been seen on cars before and appeared to coincide with sparking. However, I think it is only usually seen at night races. I can't imagine the metal getting hot enough to glow so brightly on a sunny day as this Sunday was. I also noticed it on multiple laps down the front straight and it could be seen all the way down to turn 3. I don't think glowing metal would stay that hot for that long. For example, I'm pretty sure glowing brakes lose their glow pretty quickly even through low speed corners.

Could you provide a screen capture of those laps, excluding the one in which Alonso was overtaken?

I only have access to the Channel 4 highlights and it has something that disables screen captures on it. But having gone through it just now I think you are actually correct it is only seen when he overtakes Alonso. The sunlight appears to reflect off that part of the car later in the race which can be seen on all cars but is a bit brighter on the Mercedes. Definitely not a sensor though unless they only turned it on when he overtook Alonso.

[wjpbill]

They’ve used it before, it’s a sensor. I’ve asked the question of the team to try and get a definitive answer.

https://twitter.com/scarbstech/status/ ... Fubpuzd8Qg

[matteosc]

Mercedes main engine coolant radiators are definitely lower set than Ferraris

Those may be slightly lower, but the ones in the airscope are a lot higher. It is not a secret that shrinking sidepodes comes with compromises in terms of radiator positioning and center of gravity.

There’s no rads up high in the air scoop, the engine cover got wider because that is their hot air exit to the rear.

OK, this is just getting silly.

[OO7]

They’ve used it before, it’s a sensor. I’ve asked the question of the team to try and get a definitive answer.

https://twitter.com/scarbstech/status/ ... Fubpuzd8Qg

That would be helpful wjpbill. I appreciate the link as I wasn't aware of that type of sensor, but more the version that emits a very strong white light, having seen them being used particularly during testing and also FP sessions.

Thanks for asking the team/Scarbs. I hope they're aware of the context (only visible once after heavy sparking) as similar sensors may have been placed around other parts of the car that were visible at all.

[vorticism]

Those may be slightly lower, but the ones in the airscope are a lot higher. It is not a secret that shrinking sidepodes comes with compromises in terms of radiator positioning and center of gravity.

There’s no rads up high in the air scoop, the engine cover got wider because that is their hot air exit to the rear.

OK, this is just getting silly.

He's right, you'll have to go through the threads to see the images, but the Merc central radiator is mounted low and horizontally, compared to RB/TR/Alpine which have higher diagonal radiators up "in the air scoop." Also the Merc radiators are widest at their base near the floor, which means that their sidepod radiators also have a relatively lower center of gravity.

[matteosc]

There’s no rads up high in the air scoop, the engine cover got wider because that is their hot air exit to the rear.

OK, this is just getting silly.

He's right, you'll have to go through the threads to see the images, but the Merc central radiator is mounted low and horizontally, compared to RB/TR/Alpine which have higher diagonal radiators up "in the air scoop." Also the Merc radiators are widest at their base near the floor, which means that their sidepod radiators also have a relatively lower center of gravity.

And Ferrari still has no radiators up there. Lower than RB does not mean much, since the whole conversation started with Ferrari/Mercedes COG.

Looking at this thread seems like Mercedes has the lowest center of gravity, the higher downforce levels and the best engine. Weird, considering track performance.

[vorticism]

And Ferrari still has no radiators up there. Lower than RB does not mean much, since the whole conversation started with Ferrari/Mercedes COG.

Looking at this thread seems like Mercedes has the lowest center of gravity, the higher downforce levels and the best engine. Weird, considering track performance.

Yet they are not so far off, and reliability counts in this formula, they've excelled with that since 2014. I do wonder if porpoising is over emphasized. It seems to only occur at high speeds on straights, so it would seem the only drawback is driver comfort.

All told, if you factor in that the Ferrari sidepod radiators are more horizontal, and therefore lifted up off the floor to fit them, compared to Merc, with their more vertical sidepod radiators that are wider at the base and fitted all the way to the floor, they may not be so far off from each other. There are some images out there of the Merc sidepod radiators, they are barely a four inches wide at the top maybe.

[OO7]

They’ve used it before, it’s a sensor. I’ve asked the question of the team to try and get a definitive answer.

https://twitter.com/scarbstech/status/ ... Fubpuzd8Qg

wjpbill, again thanks for that link. I've reviewed the footage from the picture in Scarbs' tweet. It came from roughly 10 minutes into FP2 during the Saudi GP last year. I'm actually more convinced after seeing it that the glow is produced from skidblock incandescence or if possible (and I have no idea of the physics behind my next theory so I could be way off), some sort of interaction between a hot skid block and the optical sensor that makes the sensors light more visible when the area immediately surrounding it becomes extremely hot.

The reason I'm more convinced after watching the 2021 Saudi FP2 footage, is because the car is shown grounding and sparking heavily around the gentle, flatout left curve leading towards the final corner T27. The sparks are seen to emanate from the righthand side of the bib, which makes sense as that part of the circuit is a lefthand curve, which causes the car to roll to the right, meaning the right side of the car and bib is closer to the surface and or creates more friction on the right side of the skid block. Into the braking area for T27, after the sparking has stopped and the car is steered into the corner, the same glow we've been discussing is visible, yet unlike Australia where it emanated from the centre of the bib (That car was travelling in a straight line), in Saudi it was offset to the right at the same spot the sparks were being generated. Here are a sequence of stills from the footage:

NOTE: The the car had been sparking and grounding for a while before the picture shown in the first still.

In this first image, that very small bright spot under the bib, that's offset to the right (our left), is the car sparking.






Unfortunately almost the entire lap is shown onboard with the exception of the run down to T27 I described, so there's no way to know how the bib looked at other points during the lap. I'm also aware that some may argue that the sensor was installed offset to right, which may be valid.

[VacuousFlamboyant]

In this regard, Ferrari success may be misleading. Ferrari has porpoising, but their concave sidepods (and underbody) is less susceptible to porpoising ups and downs as it might absorb some of the detached flow better, thus creating less drag. Something that is exacerbated in the Mercedes by the excess of suspension work and the center of gravity being placed further down, rather than the sidepods themselves.

I do not think that Mercedes has a lower center of gravity than Ferrari. On the contrary, Ferrari has way less mass behind the airscope and all radiators are generally positioned lower than Mercedes.

Poor choice of words. I do not think of the center of gravity as a static point in my mind. I do think Merc COG is slightly higher because the central radiator is twice the volume of the one in the Ferrari. What I meant is the COG shifts weigth backwards in relation to the pressure distribution around the sidepods (whole car) and lifts the front, affecting the floor.
Sorry for the late post, I did not see your reply.

[OO7]

Okay. I think I have to raise my hand and say I got it wrong. I think e30ernest called it correctly in this post viewtopic.php?p=1054475#p1054475.

I reviewed the Saudi footage again in slow motion and while at normal speed the sparking looks fairly constant, in slow motion it's more on and off as the skidblock travels over bumps on the track surface. During the off periods there is no glow from the bib at all, until fractions of a second after the car starts braked for T27 and there's a brief shower of sparks from the bib. It's only at this point the glow comes on. It seems the sensor was placed offset or is directional.

Again I've got to admit I got this one wrong. Sorry for dragging it out guys.

[matteosc]

In this regard, Ferrari success may be misleading. Ferrari has porpoising, but their concave sidepods (and underbody) is less susceptible to porpoising ups and downs as it might absorb some of the detached flow better, thus creating less drag. Something that is exacerbated in the Mercedes by the excess of suspension work and the center of gravity being placed further down, rather than the sidepods themselves.

I do not think that Mercedes has a lower center of gravity than Ferrari. On the contrary, Ferrari has way less mass behind the airscope and all radiators are generally positioned lower than Mercedes.

Poor choice of words. I do not think of the center of gravity as a static point in my mind. I do think Merc COG is slightly higher because the central radiator is twice the volume of the one in the Ferrari. What I meant is the COG shifts weigth backwards in relation to the pressure distribution around the sidepods (whole car) and lifts the front, affecting the floor.
Sorry for the late post, I did not see your reply.

Longitudinal position of COG is essentially fixed by regulation (vertical is not, obviously). You can have minor differences from full fuel to empty tank depending on fuel tank location, but the horizontal position is extremely similar for all cars.
Pressure distribution, both on the top of the car and under the floor can be instead radically different and I would assume that most of the car "balance" is given by the pressure distribution rather than COG longitudinal location.