12. GP DE HUNGRIA 2023

[taik]

Este hilo para la teoria de los neumaticos cambiados

Dr Obbs - @dr_obbs (19 july)

At the #BritishGP in Silverstone, we saw many teams running aerodynamic rakes in FP1. Was this only to do with minor aero part updates, or was there something more going on? I have a theory... ?



Before the race,
@pirellisport
announced they would bring a new specification of tyre to add rigidity & strength to the build. It wouldn't impact performance characteristics, but would be more suited to the higher downforce teams were generating. So what's this to do with aero?



First we should talk about the aerodynamics of air moving around a rotating tyre. It's quite complex, so simply put, air moving around any bluff body will always create a wake. The wake consists of undesirable low energy flow structures that fill in the energy deficit..

Left behind the tyre as dynamic energy is lost due to tyre drag. Typically upper, mid, and lower vortical structures form as the flow wraps around the tyre filling in this low energy deficit. During cornering, the geometry of the tyre changes under load complicating the matter.


So why do we care? As the underside of a race car is predominantly responsible for the bulk of the downforce, high energy flow is desired to maximize the efficiency of this process. This is why teams employ different tactics to try and outwash this tyre wake away from..


The downforce generating parts of the floor. Here, I don't show the Front Wing influence, but this is a key area of development as well. Ok, so now we know, Front Tyre wake is bad. But what's changed now with the new tyre construction required teams to run aero rakes?


In a SAE paper in 2012 (referenced below), the researchers assessed the influence of tyre pressure on tyre wake structures. The paper determined that the deformation of the tyre does influence downstream wake structures. Sensitivity to the tyre deformation model was greatest. Therefore, my theory is the new Pirelli construction could also bring some teams aero problems changing the location of the wake structures behind the tyre. This might explain why teams ran aero rakes with the new tyre. Correlation with updated CFD models would be key also.



So might we see some further FW updates to mitigate changes introduced by the behavior of the new tyres? It's an interesting thought to consider, & one not many people are talking about.