The flow under the floor is still greater than free stream flow, so the system has a boundary layer from the free stream at the ground up to the accelerated airspeed. The teams will likely use the underfloor fences to transport momentum from some space of high momentum into the boundary layer of this surface. That allows them to create a steeper expansion out the back and subject that boundary to a steeper pressure gradient. The primary effect of these fences is to maintain the desired flow field for a steeper exit angle of curvature at the back of the car. However, as teams add to those fences, the drag increases from the shed vortices, but the more expansion they’re going to create out the back and more downforce. Understanding where drag originates and hurts performance, how strong the vortices are and whether there is a need to shed these to hit the maximum curvature that the rules allow is critical.
Diffuser trailing edge control
As per the 2021 technical regulations,…
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