Mercedes W13

[fritticaldi]

The car shakes so bad (Its by far the worst of the lot) that its likely Hamilton & Russell will have back problems or Neck problems. Physically too demanding. Another scenario : Maybe they wont be able to complete the race. There is onboard video footage and you see the drivers helmets bobbling like crazy.

[AMG.Tzan]

Can't believe a team of Mercedes's caliber cannot solve such a problem! They have the worst porpoising of any other team...

[TwanV]

As an engineer I like any solution that would give me the most options in an uncertain situation; Mercedes has this position currently, if they didn’t totally screw up the mass balance they have by far the most potential for improvement during the season: any side pod will do. It’s going to be an interesting year. Bar sandbagging, if they are behind now they won’t be in three races from now and that should make us all very happy

[Dee]

Okay, I put in centre of mass and porpoising into google and came across this interesting post in a boat design forum

https://www.boatdesign.net/threads/porpoising.1155/

Not cars obviously but seemingly the same thing happening

"I have a problem with porpoising on my 12' home-built duckboat whenever I get above 3/4 throttle. I am particularly interested in the center of gravity/center of lift relationship.

Doesn't moving weight forward only lessen the frequency of the occillation in accordance with consevation of angular moment. From what I've gleaned so far, and correct me if I'm wrong, here are the dynamics of porpoising: The boat has a fixed center of mass (COM). The hull has a center of boyancy (COB) that moves aft as the wet surface of the hull decreases at higher speeds. As the COB passes aft of the COM, gravity pulls the bow down rotating on the COB point. When the bow goes down, the COB immediately and rapidly moves forward of the COM. Stability is reestablished until the COB once again moves aft of the COM.

Moving weight forward, if my thinking is correct, should only increase the likelyhood of porpoising. Though initially this might bring the bow down, and hence, move the COB forward until speed is ultimately increased enough to shift it aft of the COM again, the forward shift of the COM only appears to deminish porpoising because as the radius of arc of the ocillating COM about the COB increases, the frequency of occillation decreases to preserve the angular moment.

Trim in causes the craft to run in a more bow down attitude which serves to keep the COB forward. Porpoising is prevented until enough power is applied to move the COB aft again.

This leave me with the counterintuitive solution of moving weight aft so as to move the COM aft.

There is the possibility of my boat being overpowered (by definition of this particular instability) which moves the COB aft to the extreme, and more so than any aft movement of the COM that I would be able to achieve.

In line with my thinking, the reason that a rocker hull is thought to porpoise more is because the bow rides high, and therefore, has further to fall making porpoising more pronounced as opposed to making it more likely.

I guess the trick then is to balance weight distribution, trim attitude, and power for the most efficient use of thrust."

Obviously a boat not a car but generally the same issue and a very interesting insights

[fritticaldi]

There are reports the problem could take 5 months to fix. https://www.motorsportmagazine.com/arti ... t-up-issue

[andrewf1]

There are reports the problem could take 5 months to fix. https://www.motorsportmagazine.com/arti ... t-up-issue

There are no such reports, that's just a quote by Russell, who also said their issue might get sorted this afternoon. His predictions don't mean much.

[PlatinumZealot]

Nothing is wrong with the centre of mass of the car.

Shovlin said it's the porpoising and the balance. Meaning aerodynamic problems.

Mercedes if anything, has the best packaging on the grid. It would be the easiest thing to test mass balance by adding weights in the front wing, in the bib, in the plank etc.

[Dee]

Nothing is wrong with the centre of mass of the car.

Shovlin said it's the porpoising and the balance. Meaning aerodynamic problems.

Mercedes if anything, has the best packaging on the grid. It would be the easiest thing to test mass balance by adding weights in the front wing, in the bib, in the plank etc.

I don't know you can say that centre of mass has nothing to do with aerodynamics when the issue being solved is porpoising

[Just_a_fan]

There are reports the problem could take 5 months to fix. https://www.motorsportmagazine.com/arti ... t-up-issue

No there aren't. There's a driver using an English exaggeration idiom for effect.

[ltitus8900]

The car shakes so bad (Its by far the worst of the lot) that its likely Hamilton & Russell will have back problems or Neck problems. Physically too demanding. Another scenario : Maybe they wont be able to complete the race. There is onboard video footage and you see the drivers helmets bobbling like crazy.

I honestly think that there is a "grey goose" in what Merc is saying. I think that they are experiencing the issue far more than the other teams because they are making far more downforce. I'm assuming based on the car's behavior relative to the others, their downforce is not capable of being solved by floor detail without loosing to much downforce. They are most likely doing what Scarbs said. They can probably mitigate the issue now but are pushing resources towards making a new suspension.

So though they have no quick fix, they will more than make up for it once the suspension arrives. I am current building a model in blender to run through CFD. I will post some images if I like the results.

[Just_a_fan]

The car shakes so bad (Its by far the worst of the lot) that its likely Hamilton & Russell will have back problems or Neck problems. Physically too demanding. Another scenario : Maybe they wont be able to complete the race. There is onboard video footage and you see the drivers helmets bobbling like crazy.

I honestly think that there is a "grey goose" in what Merc is saying. I think that they are experiencing the issue far more than the other teams because they are making far more downforce. I'm assuming based on the car's behavior relative to the others, their downforce is not capable of being solved by floor detail without loosing to much downforce. They are most likely doing what Scarbs said. They can probably mitigate the issue now but are pushing resources towards making a new suspension.

So though they have no quick fix, they will more than make up for it once the suspension arrives. I am current building a model in blender to run through CFD. I will post some images if I like the results.

If it's too much downforce, could less aggressive wings be the answer? That would also give less drag meaning a slippery car. A possible double win.

[dialtone]

The car shakes so bad (Its by far the worst of the lot) that its likely Hamilton & Russell will have back problems or Neck problems. Physically too demanding. Another scenario : Maybe they wont be able to complete the race. There is onboard video footage and you see the drivers helmets bobbling like crazy.

I honestly think that there is a "grey goose" in what Merc is saying. I think that they are experiencing the issue far more than the other teams because they are making far more downforce. I'm assuming based on the car's behavior relative to the others, their downforce is not capable of being solved by floor detail without loosing to much downforce. They are most likely doing what Scarbs said. They can probably mitigate the issue now but are pushing resources towards making a new suspension.

So though they have no quick fix, they will more than make up for it once the suspension arrives. I am current building a model in blender to run through CFD. I will post some images if I like the results.

If it's too much downforce, could less aggressive wings be the answer? That would also give less drag meaning a slippery car. A possible double win.

I very much doubt it's too much downforce for a few reasons:
* They would be far and away the best in slow speed corners but at best they are equivalent to FER and RBR in S2 here.
* It would start porpoising earlier than other teams because the car is squatted faster due to stronger downforce.
* They won 8 WCC in a row, if the solution was take out some wing, they would have done it already.

I would instead assume that, if a team like Merc hasn't gotten to the bottom of it yet, it's because the problem is a lot more complicated than it seems, it likely deals in performance trade offs and they might not be able to give up some of the performance to fix it.

[PlatinumZealot]

Nothing is wrong with the centre of mass of the car.

Shovlin said it's the porpoising and the balance. Meaning aerodynamic problems.

Mercedes if anything, has the best packaging on the grid. It would be the easiest thing to test mass balance by adding weights in the front wing, in the bib, in the plank etc.

I don't know you can say that centre of mass has nothing to do with aerodynamics when the issue being solved is porpoising

Specsavers or Zenni? Which one do you like? Gonna send you a pair.

[AR3-GP]

Nothing is wrong with the centre of mass of the car.

Shovlin said it's the porpoising and the balance. Meaning aerodynamic problems.

Mercedes if anything, has the best packaging on the grid. It would be the easiest thing to test mass balance by adding weights in the front wing, in the bib, in the plank etc.

I don't know you can say that centre of mass has nothing to do with aerodynamics when the issue being solved is porpoising

I think we don't understand the full nature of Mercedes porpoising.

If it is a pure heave porpoising, then the center of mass doesn't matter. If there is a pitching component in the porpoising, then center of mass will change the pitching dynamics, but the fundamental origin of the porpoising is the floor stalling, not the center of mass. It would porpoise even if the center of mass was on the skidblock.

[dans79]

Nothing is wrong with the centre of mass of the car.

Shovlin said it's the porpoising and the balance. Meaning aerodynamic problems.

Mercedes if anything, has the best packaging on the grid. It would be the easiest thing to test mass balance by adding weights in the front wing, in the bib, in the plank etc.

I don't know you can say that centre of mass has nothing to do with aerodynamics when the issue being solved is porpoising

I think we don't understand the full nature of Mercedes porpoising.

If it is a pure heave porpoising, then the center of mass doesn't matter. If there is a pitching component in the porpoising, then center of mass will change the pitching dynamics, but the fundamental origin of the porpoising is the floor stalling, not the center of mass. It would porpoise even if the center of mass was on the skidblock.

I think it's purely floor driven. People like to make a big deal about the center of mass on F1 cars, but it really doesn't very that much from what I've seen, and definitely not enough to cause the type of issue we have seen through testing!