The more I think about this the less I think its caused by aero effects, regardless of whether its intentional or not. The footage of the Williams pitting proves for me that 1) there is a non aero related source of significant vibration because that car isn't travelling fast enough to have significant aero forces and 2) the rear wing oscillates readily without much input. Another argument against aero causes is that the frequency with which the vortex sheet shed is a function of velocity, so you would expect the natural frequency to be hit for only a portion of your trip down the straight, not the whole way. The yaw idea occurred to me too but I pretty much ruled that out on the basis that this effect is most pronounced when the car is travelling in a straight line then braking. I think a lot of us like discussing aero so we are just jumping to it like aero engineers rather than vehicle dynamicists.flyboy2160 wrote:I was thinking about the airflow in yaw vis a vis the endplates. That is, a big yawing direction could make them bluff/stall in that direction. But the more I think about it, the less likely that seems.
Which leads me to my latest theory (I know I've had many, I speak too soon without thinking any of them through it seems, I'll probably be throwing this theory out in the next few hours): this seems to occur most under braking, especially heavy braking, which got me thinking how can you get a vibration that big from a mechanical component - my guess is the way the energy recovery systems work this year the flywheels are pretty big and have a fair bit of inertia, as well as having a huge non-axisymetric fitting on the end. From a packaging perspective I imagine they aren't perfectly centred in the car and it would also explain why this year the vibrations are so significant.