AlphaTauri introduced the second part of its upgrade package in Portugal, the first items of which appeared in Imola, with further developments to follow this weekend in Barcelona. This came in the form of a revised diffuser, although it was not used in qualifying or the race. The windy conditions in Portimao make back-to-back testing difficult, as there is increased uncertainty in measurements from an already noisy environment compared to the wind tunnel and particularly CFD. Therefore, it is possible it will be re-tested this weekend.
The changes concerned the outboard of the diffuser, and were fairly subtle. Firstly, the trailing edge angle of the outboard of the diffuser was increased, effectively raising the expansion of this region. This would have slightly worsened the shear stress right at the trailing edge, but perhaps there was some margin on this previously, allowing a more aggressive approach.
As there is more upwash from the main diffuser itself, the double element flap above it has more support, and therefore can be pushed harder while remaining attached, further increasing expansion. This displays the connection between various elements of the car, and the fact that one area cannot be changed in isolation without optimisation elsewhere.
Finally, the legalisation method employed in the outboard upper corner of the diffuser flaps has been altered, following the trend seen on most cars on the grid. This stay serves two purposes – firstly, it satisfies continuity between the two flaps, and secondly, it shadows the region of the highest/most outboard flap above a horizontal plane at 175 mm above the reference plane, when looking from beneath the car. The new method should reduce flow losses and lower blockage behind/above the diffuser, slightly increasing load.
Racing Tech 