Sunday, May 08, 2005
For Spain the side walls of the diffuser have been extended, with vertical ends instead of sloped one (see yellow line). This allows for an additional profile (see red arrow) that creates a sort of double channel (one above the other). This provides more efficient air extraction from beneath the car, increasing the speed of airflow on exit. This generates additional downforce and should provide more rear-end stability.
A change for Barcelona right in front of the sidepods. Gone is the single horizontal fin featured since Melbourne. In its place is a double element, with the outer part inclined downwards, and the inner one sporting a deeply-curved upward profile. These elements are part of a continuous development of the TF105, providing more efficiency (and hence downforce) from the diffuser and the bottom of the car in general.
For Barcelona, different cooling layouts on either side of the Ferrari. The right sidepod features an open chimney to improve sidepod radiator cooling, while on the left one the chimney has been switched with a closed fin, whose main task is to improve the airflow directed to the rear of the car. This unusual layout reflects the different the cooling needs on the Circuit de Catalunya - a track with a prevalence of right handers.
In Barcelona Williams adopted a revised version of their big shields, providing them with a different knife-edged profile at the bottom. They now sport a sharper 'tooth' shape, instead of the continuous profile seen previously. This change is not dissimilar to designs used by Ferrari and Renault, splitting airflow in this area to reduce vortices and at the same time improve efficiency around the bottom of the car.
A small but interesting change for Barcelona -side 'ears', right over the push rod links. These have a similar function to the small winglets already seen on the Toyota TF105, the work of ex-Renault employee Mike Gascoyne. These 'ears' provide a small increase in frontal downforce and also provide better airflow management around the cockpit area.
A small barge-board change for Barcelona, effecting both the large shields in front of the sidepods and the smaller ones at the front-axle level. With the former, the bottom of the sidepod has now been given a forward extension similar to that introduced by McLaren after Melbourne. The link between sidepod and barge board is now a sort of neutral wing profile, improving airflow management in this area, while also increasing the structure's strength.
The car is set up with a camber angle so that the tyre becomes perfectly vertical when cornering, maximising its contact patch. This angle change is due to the chassis' roll and yaw movement - it rotates around the centre of roll (yellow and black dot). Furthermore, the lateral forces on the car when cornering (large red arrow) make it want to slide on its tyres. This is countered by the controlled deformation of the tyre shoulder (large yellow dot).
The Circuit de Catalunya runs clockwise, with left-hand tyres under huge lateral loads. Suspension is vital in reducing the stress on tyres, with the third damper fundamental to setting up the front of the car properly. This damper also affects the rear, as it reduces the car's roll and yaw sensitivity, allowing it to run with lower camber angles, increasing the tyres' contact patch, hence reducing tyre wear.
Barcelona's strong sidewinds upset a car's aerodynamic efficiency, hence teams seek to reduce sensitivity to them by minimising the side bodywork's cross-sectional area. Many, such as Williams, include a deep cut in the rear of the engine cover to act as a venting channel, through which side winds can flow with minimal disruption to the car's set-up.