2022 cars 'porpoising' at high speed

[ojir19]

https://www.motorsport.com/f1/news/russ ... n/8572024/

Russell suggests active suspension as solution to porpoising issue.

Mercedes driver George Russell thinks a return of active suspension in Formula 1 could help deliver a long-term solution to the porpoising problem of the new ground effect cars.

Russell felt that active suspension would be a good fit for the current cars, as it would help drive down lap times as well.

“I think it's clear if we had active suspension, the cars will be a hell of a lot faster for the same aerodynamic surfaces, because you'd be able to optimise the ride heights for every corner speed and optimise it down the straight for the least amount of drag,” he said.

[billamend]

https://www.motorsport.com/f1/news/russ ... n/8572024/

Russell suggests active suspension as solution to porpoising issue.

Mercedes driver George Russell thinks a return of active suspension in Formula 1 could help deliver a long-term solution to the porpoising problem of the new ground effect cars.

Russell felt that active suspension would be a good fit for the current cars, as it would help drive down lap times as well.

“I think it's clear if we had active suspension, the cars will be a hell of a lot faster for the same aerodynamic surfaces, because you'd be able to optimise the ride heights for every corner speed and optimise it down the straight for the least amount of drag,” he said.

Did Mercedes ask him to say that? I’m sure Mercedes has a solution ready to deploy once they can get the rules to be changed…

[piast9]

The solution shouldn't be too difficult, the teams just have to figure out how much air they can squeeze under the floor before it stalls at minimum ride height.

I was thinking about that too. I don't fully understand why they lose so much downforce when the suspension is compressed. Touching the ground itself should not cause major issues since you seal the tunnels better that way. Is it just because of the tunnel crossection being squeezed past their optimal point? If so they should be able to modify them to not stall so dramatically.

If they don't do that the car may behave ok for most of the situations but then start to porpoise when the car hits a bump. That may be dangerous in a situation when the racing line is smooth and the car hits a bump when overtaking.

[SmallSoldier]

The solution shouldn't be too difficult, the teams just have to figure out how much air they can squeeze under the floor before it stalls at minimum ride height.

I was thinking about that too. I don't fully understand why they lose so much downforce when the suspension is compressed. Touching the ground itself should not cause major issues since you seal the tunnels better that way. Is it just because of the tunnel crossection being squeezed past their optimal point? If so they should be able to modify them to not stall so dramatically.

If they don't do that the car may behave ok for most of the situations but then start to porpoise when the car hits a bump. That may be dangerous in a situation when the racing line is smooth and the car hits a bump when overtaking.

Not an aerodynamicist, but my interpretation of what is happening is as follows… You have air going through the tunnels, the more air you get through the tunnels (and exiting through the diffuser) the more downforce you generate… The downforce makes the cars squat (reduce the distance to the ground)… When that distance to the ground is reduced, the tunnels “choke”, meaning there is less space now for the air and therefore the amount of air traveling through the tunnel is suddenly and abruptly interrupted… This makes the car lose downforce and therefore the car raises on reference to ground… As soon as this happens, the choke is now gone and the air starts accelerating again through the tunnel, the car ones again squats and the cycle gets started again.

[djos]

https://www.motorsport.com/f1/news/russ ... n/8572024/

Russell suggests active suspension as solution to porpoising issue.

Mercedes driver George Russell thinks a return of active suspension in Formula 1 could help deliver a long-term solution to the porpoising problem of the new ground effect cars.

Russell felt that active suspension would be a good fit for the current cars, as it would help drive down lap times as well.

“I think it's clear if we had active suspension, the cars will be a hell of a lot faster for the same aerodynamic surfaces, because you'd be able to optimise the ride heights for every corner speed and optimise it down the straight for the least amount of drag,” he said.

Did Mercedes ask him to say that? I’m sure Mercedes has a solution ready to deploy once they can get the rules to be changed…

Who knows, still as an F1 fan since 85, I was seriously cheesed off when active suspension was banned and would love to see it return.

[djos]

It just occurred to me that in some racing series they use Bump-stops to control minimum ride height. How easy would it be for F1 teams to do the same?

eg:
https://www.resuspension.com/news/post/ ... thy-level/

“NASCAR was the first to do it,” he said. “We figured out that if we took all the spring rate out of the front and set the car down on the bump stops, we would keep a lower dynamic platform, which was better for aero and everything else. When we took those cars and tried to make them more like go-karts, we figured out that they worked better because, as the car travels up and down, your camber
curves and dynamic wedge numbers change. When we can take those variables out of the equation, the car works better. The car’s lower so the center of gravity is better, and the aero becomes more stable.”

The end result functions much like a dual rate or stacked spring setup might, but this approach allows for more dramatic changes than springs can typically provide. “The problem is that the rate split that we need is often very hard to do with a typical dual rate
spring,” Enders added. “And because we need to travel these cars so far, packaging can become an issue with a stacked setup. This approach is compact and easy to tune.”

[theblackangus]

https://www.motorsport.com/f1/news/russ ... n/8572024/

Russell suggests active suspension as solution to porpoising issue.

Mercedes driver George Russell thinks a return of active suspension in Formula 1 could help deliver a long-term solution to the porpoising problem of the new ground effect cars.

Russell felt that active suspension would be a good fit for the current cars, as it would help drive down lap times as well.

“I think it's clear if we had active suspension, the cars will be a hell of a lot faster for the same aerodynamic surfaces, because you'd be able to optimise the ride heights for every corner speed and optimise it down the straight for the least amount of drag,” he said.

I really hope this doesnt happen. Just what we need the car driving itself more.

[Zynerji]

The solution shouldn't be too difficult, the teams just have to figure out how much air they can squeeze under the floor before it stalls at minimum ride height.

I was thinking about that too. I don't fully understand why they lose so much downforce when the suspension is compressed. Touching the ground itself should not cause major issues since you seal the tunnels better that way. Is it just because of the tunnel crossection being squeezed past their optimal point? If so they should be able to modify them to not stall so dramatically.

If they don't do that the car may behave ok for most of the situations but then start to porpoise when the car hits a bump. That may be dangerous in a situation when the racing line is smooth and the car hits a bump when overtaking.

Not an aerodynamicist, but my interpretation of what is happening is as follows… You have air going through the tunnels, the more air you get through the tunnels (and exiting through the diffuser) the more downforce you generate… The downforce makes the cars squat (reduce the distance to the ground)… When that distance to the ground is reduced, the tunnels “choke”, meaning there is less space now for the air and therefore the amount of air traveling through the tunnel is suddenly and abruptly interrupted… This makes the car lose downforce and therefore the car raises on reference to ground… As soon as this happens, the choke is now gone and the air starts accelerating again through the tunnel, the car ones again squats and the cycle gets started again.

So they need a pre-diffusor BOV feeding a double deck.

[SmallSoldier]

I was thinking about that too. I don't fully understand why they lose so much downforce when the suspension is compressed. Touching the ground itself should not cause major issues since you seal the tunnels better that way. Is it just because of the tunnel crossection being squeezed past their optimal point? If so they should be able to modify them to not stall so dramatically.

If they don't do that the car may behave ok for most of the situations but then start to porpoise when the car hits a bump. That may be dangerous in a situation when the racing line is smooth and the car hits a bump when overtaking.

Not an aerodynamicist, but my interpretation of what is happening is as follows… You have air going through the tunnels, the more air you get through the tunnels (and exiting through the diffuser) the more downforce you generate… The downforce makes the cars squat (reduce the distance to the ground)… When that distance to the ground is reduced, the tunnels “choke”, meaning there is less space now for the air and therefore the amount of air traveling through the tunnel is suddenly and abruptly interrupted… This makes the car lose downforce and therefore the car raises on reference to ground… As soon as this happens, the choke is now gone and the air starts accelerating again through the tunnel, the car ones again squats and the cycle gets started again.

So they need a pre-diffusor BOV feeding a double deck.

Lol… Well they kind of did that with the cuts on the floor to release some flow before it got choked

[SmallSoldier]

Video by The-Race in regards to McLaren use of vortices to seal the floor and avoid porpoising, as well as comparison to the other big 3 teams:

[Just_a_fan]

Video by The-Race in regards to McLaren use of vortices to seal the floor and avoid porpoising, as well as comparison to the other big 3 teams:

Did they use images from this forum in that video? Or did the negative images come from elsewhere before hitting the forum's pages?

[the EDGE]

Video by The-Race in regards to McLaren use of vortices to seal the floor and avoid porpoising, as well as comparison to the other big 3 teams:

Did they use images from this forum in that video? Or did the negative images come from elsewhere before hitting the forum's pages?

Vice versa I’m afraid, they were taken from the Race in the first place

[Just_a_fan]

Video by The-Race in regards to McLaren use of vortices to seal the floor and avoid porpoising, as well as comparison to the other big 3 teams:

Did they use images from this forum in that video? Or did the negative images come from elsewhere before hitting the forum's pages?

Vice versa I’m afraid, they were taken from the Race in the first place

Ah, OK.

We have had examples of commercial sites making use of stuff created on this forum which is why I asked.

[piast9]

Not an aerodynamicist, but my interpretation of what is happening is as follows… You have air going through the tunnels, the more air you get through the tunnels (and exiting through the diffuser) the more downforce you generate… The downforce makes the cars squat (reduce the distance to the ground)… When that distance to the ground is reduced, the tunnels “choke”, meaning there is less space now for the air and therefore the amount of air traveling through the tunnel is suddenly and abruptly interrupted… This makes the car lose downforce and therefore the car raises on reference to ground… As soon as this happens, the choke is now gone and the air starts accelerating again through the tunnel, the car ones again squats and the cycle gets started again.

So our understanding is similar. Then what stops the teams from making the tunnels a bit larger so they do not choke when the car bottoms down? I assume they loose a bit of the downforce but it may be worth it if drivers have more consistent feeling of their cars.

[vorticism]

Not an aerodynamicist, but my interpretation of what is happening is as follows… You have air going through the tunnels, the more air you get through the tunnels (and exiting through the diffuser) the more downforce you generate… The downforce makes the cars squat (reduce the distance to the ground)… When that distance to the ground is reduced, the tunnels “choke”, meaning there is less space now for the air and therefore the amount of air traveling through the tunnel is suddenly and abruptly interrupted… This makes the car lose downforce and therefore the car raises on reference to ground… As soon as this happens, the choke is now gone and the air starts accelerating again through the tunnel, the car ones again squats and the cycle gets started again.

Since there is both a floor and the plank which define the lowermost vertical travel of the tunnels, fully bottoming out the suspension and dragging the plank on the ground would still permit flow within the tunnels; it seems it would be a question of whether or not having less lateral flow into nor out of the tunnels should raise the pressure within the tunnel. If lateral flow out of the tunnels in the mid-section of them is relied upon for their overall performance then perhaps less air travels through them as ride height reduces.