Red Bull arrived in Portugal with a significant upgrade package, comprising a revised front brake duct, bargeboard and floor. Due to the nature of the asphalt at Portimao, it was difficult to understand the effect of the developments, though this should become clearer in Barcelona this weekend. The fact that the new parts were raced by both cars, after the team ran a back-to-back comparison in FP1, suggests that they worked as expected.
Regarding the front brake ducts, the inlet now features an additional duct, while the overall outline is unchanged. While some of these ducts are required for brake cooling, much of the flow taken in is used to outwash the front tyre wake, and this change perhaps looks at better optimising the flow out through the front wheel.
Looking at the bargeboards, some detail changes were made to the devices along the footplate, with the number of elements increased by one and the forward ones more nose-up, probably in an attempt to better align them to the oncoming flow. Introducing an extra element here should improve the flow quality underneath the floor. Note also that one of the sets of mini-bargeboards now features an extra element, although the details of this are unclear given the lack of photos of the new bargeboard region.
Additionally, the leading edge of the main bargeboard is now shaped differently. Previously this region was much thicker due to the need to house a pad for the attachment of the bargeboard to the T-tray. However, this has now been moved further rearward, allowing more freedom in the design of the forward extension of the bargeboard. This extension generates some local load as the onset flow has both downwash and outwash, induced by the Y250 vortex.
The sidepod vanes have been developed fairly extensively, with a number of changes. The largest visual one concerns the leading element sweeping forward to connect to the base of the bargeboard region, while also including a slot. Due to the outwash from the bargeboards, and the fact that this element turns the flow back towards the longitudinal axis of the car, it will have some suction on a partly forward-facing surface, helping to reduce drag. The slot should allow this effect to be more pronounced without causing flow separation issues. By making this change, the lower horizontal elements can be widened, which should provide a local load benefit while also increasing the static pressure inboard of them, keeping the front tyre wake at bay. Finally, the rearward vertical element has been extended down to the top of the floor. This may offer some structural benefits, and could also help pressurise the region further inboard.
Looking at the edge of the floor, the upwashing curl and the double element flap above it have been extended further rearward, now reaching the long outwashing vane that marks the stepped transition of the floor edge position in an overhead view. This should increase load by increasing the mass flow under the forward floor and bargeboard system, potentially at the expense of some rear downforce due to increased flow losses. The vortex shed by the long outwashing vane should also be stronger due to the increased pressure difference across its tip.
Finally, on the diffuser, the central region now features a significantly greater lateral expansion, evidenced by the narrower middle section. Increasing the expansion will enhance the suction around the rear of the plank, thereby better connecting the low pressure peak here to that of the main kick line that starts further forward, 175 mm ahead of the rear wheel centreline. The downside of this is that the subsequent adverse pressure gradient is worse, and the means to control this are reduced by the trimmed inboard fences for 2021.
The middle section does not have to be narrower to geometrically allow a greater initial lateral expansion, but it helps in managing this adverse pressure gradient. Although the limited view of the fences on the new design shows them to be similar to the previous ones, it would be surprising if there weren’t at least subtle design changes to improve the pressure recovery.
Racing Tech 