ANALYSIS: What is ‘porpoising’ – and why is it causing the F1 teams a headache at 2022 pre-season running?
The word ‘porpoising’ is back in fashion in F1, having been largely missing from the vocabulary for the last 40 years – when we last had ground effect cars...
Virtually every team was complaining of the phenomenon on the first day of running for the new generation of cars.
A violent bouncing on the suspension at high speeds is what the driver feels. The cause is an aerodynamic one, where either the leading edge of the floor, or perhaps the front wing, is pushed ever closer to the ground as the downforce acting upon it increases. The closer to the ground it gets, the more powerful the ground effect is, as the air rushes ever-faster through the shrinking gap.
This increases the pressure difference between the underside and upper surfaces, so increasing the downforce yet more – until it stalls. At which point, much of the load is suddenly released, the front of the car rises up suddenly in response – which allows the ground effect to begin working again! Repeat in cyclic fashion until it’s time to brake for the corner...
With much more underbody downforce, stiffer suspensions and stiffer tyres (so not as much cushioning effect) the problem has returned with a vengeance. None of the teams had seen this effect in simulation. In a wind tunnel, even the stiffest belt of the rolling road is more flexible than the track surface, and accurately modelling the dynamics of the springs and dampers in this situation is not really possible.
So, the teams are now back in the same position as the early ground effect pioneers of the late 1970s/early 1980s of trying to make the underside of the car a little less switch-like and critical – either through changing the shape of the surfaces or adjusting the suspension.
Ironically, the hydraulic tricks of the suspensions which have just been banned would have been very useful in this…
Watching how the teams cope with this unforeseen demand will be fascinating. But cope with it they surely will.