Friday, January 4, 2013

Sauber – Japanese Front Wing Analysis

Sauber have been a leader in aerodynamics this year, with the C30 gaining many compliments from other F1 engineers. With revisions to their front wing this weekend In Japan, it seems good time to delve a little deeper into the complex design of the wing. Their current wing dates back to the Spanish GP and has several features unlike any other on the grid. In Japan the wing gained a new winglet added to the cascades and a small change to the main endplate/

The C30 aerodynamics are just about all new since the cars launch. With the cars initial aero design being directed by the now departed Technical Director James Key. Aero design is led by Willem Toet, who has been directing the updates that have appeared since the start of the season.

The Original Mugello\Spanish Spec Front Wing

The basic front wing was part of the package tested at Mugello ahead of the Spanish GP. This update included the revised sidepod package, going away from the Coanda ramped set up, for a McLaren style outlet.

The underwing fence curves over to form a fourth element, underneath the main three element wing

It at first appears to be a three element front wing. But sitting under and behind wing is another element. In unpainted carbon fibre, this flap is formed by the under wing fence curving around and joining to the endplate. The horizontal section this creates makes the a 4 element design. This approach is clever as this element reaches to the rearmost allowable point for the wing to fit into. But by being underneath the main wing profiles, it can make the wing chord effectively longer, but not higher than the rules allow. The extra effective length of the wing allows the outer span to create more downforce from the limited space available within the regulations.

The unusual line of the slot gaps is evident when the cascaded are removed

The wing is unique in the layout of the slots and flaps, which encourage the outswept airflow around the front tyres. In plan view it’s clear to see how the heavily loaded outer tip of the wing, sends its wake outboard of the front tyre. The line of slots across the wing form a distinct kink in between the inner and outer spans. The outer span of the wing is a effectively a four element wing. Then with the way the flap merges into the rest of the wing, the wing the inboard section is a three element wing. This inner span of wing is not worked as hard as the outer span, in order to keep the flow along the centre of the car as undisturbed as possible.

The line of the slot gaps and the endplates curvature sends the wake out wide around the front wheel

As is common for most teams, only a small section of the flap is adjustable for angle-of-attack. In Sauber’s case the adjustment mechanism being inside a fin joining the flap at the rear of the wing.

From underneath the wing we can see the footplate is thinned to just a thin metal section at its leading edge. While the outboard section of footplate, takes the classic tunnelled approach, to create the vortices for sealing and creating a strong outswept flow around the front tyre.

Up until Japan Sauber had only a single stack of cascade elements, the two element winglet mounted to the end vane being aided by a bi plane element above it. No inner cascades or vanes were used.
For Suzuka the main cascade had a slightly revised shape, the inner section of winglet now being a distinct endplate rather than the winglets curved up to form an endplate. To this a small two element winglet has been added, the extra load put into the cascade meant that the small support under the assembly has been moved outboard. The other change for Japan was the main section of front wing endplate gained an extension, such that the vertical trailing edge is now wider and more vertical.

The sum of these changes is probably more about flow management than producing a particularly greater amount of downforce. As Suzuka is such a demanding aero circuit this is a good point to introduce these changes.


Marcel Balsa Lorenzo Bandini

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