SIMULATION
The porpoise effect It’s nothing new, but what exactly is it, and how do you deal with it?
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By Danny Nowlan
Porpoising has been one of the main topics of conversation amongst professionals and lay persons since the new generation F1 cars hit the track earlier this year, but Danny’s seen it all before
M
otorsport-wise, one of the key problems that has emerged from early season testing of the new generation Formula 1 cars is so-called porpoising. Given that myself and ChassisSim customers have dealt with this to some degree over the years, I’ve had a wry giggle at the number of lay punters out there who think this is a new thing. Porpoising has been around for a good while now, and is one of the things that’s always lurking around the corner if
you run a high-downforce racecar. In this article we’ll discuss what it is and, more importantly, how you can deal with it. First things first. If you insist on running a high-downforce racecar that is passive, the risk of porpoising is the price you pay. It doesn’t matter whether you’re running ground effect tunnels or flat bottoms, if you have either very badly conditioned aerodynamics, or a badly tuned spring / damper package, it will make its presence felt at some point.
What porpoising refers to is low-tohigh frequency oscillation in the pitch mode of the sprung mass of the vehicle. To illustrate this, Figure 1 shows how downforce is generated on a racecar. The two ways you generate downforce are by accelerating air under the car or over the rear wings. The latter is tied quite closer to the former, but we are nitpicking. When a car is prone to porpoising, from an aerodynamic perspective you have two culprits. Either the front wing / splitter
Porpoising… is low-to-high frequency oscillation in the pitch mode of the sprung mass of the vehicle 32 Formula 1 2022 • Racecar Engineering
