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Sport-Prototype - A Childhood Dream (Part 2)

by

Antonio Eiras

For its new challenge, of winning Le Mans with a car powered by a Diesel engine, Audi took the excellent, and well proved, base of the R8 to improve everything that was left to be improved.

 

Compared with its ancestor, the new car has a chassis with a narrower front section, a new and more sophisticated front part, more complex side pods, that reveals a great work in internal fluid dynamics, and a well designed rear section, apparently more effective.

 

As we can see in the drawings, made with the photographic documentation that we have on the R10, together with the Technical Regulations of the ACO, the air that flows over and around the new Audi, has to overcome, first, a very complex and interesting front part of the car.

 

Here we find a first splitter that separates the fast air flow that goes under it, from the one that is stopped against the almost vertical front wheels fender, and against the vertical surface between the front fenders (drawings 2 and 3). A pressure differential will be generated here, with consequent downforce that will be applied over the front axle.

 

As we can easily see, the leading edge of this splitter is also the leading edge of a camouflaged inverted wing, that extends backwards to overcome the front axle.

 

On both lateral extremes of this wing, we can find two flux deviators, with little splitters on their inferior borders that channel the air that flows under the wing to the big side pods fences (drawings 5 and 6).

On the trailing edge of this camouflaged wing the air that flows over the wing will blow the air flow that flew under the same wing, accelerating this flux and improving this wings efficacy by the increase of downfoce generation (drawing 5).

 

On the upper face of the front wing, we can see, internally limited by small red flux deviators, the air intakes for cooling the front brakes.

 

Just ahead of the front wheels, the under floor surface of the bodywork turns slightly upwards, in order to create a small diffuser, in lateral continuity with the front wing that improves the splitters efficacy, by accelerating the air that flows under that splitter.

 

In drawing 4 there is a schematic view of the positive effect induced over the air that flows under the front wing, by the rotation of the front wheels. The rotating wheels will aspirate part of this air flow and will drag it to the louvers open in the highest par of the front wheels cover bodywork. Here, the same air flow is, again, aspirated by the very fast and low pressure air that flows over the bodywork, and has been accelerated during the climbing of the front fender.

 

In the same drawing is explained the way the two dive plates work. Used at Sebring, but not in Le Mans, these two small delta wings generate an additional downforce over the front axle, by the effect of the small vortexes created under their leading edge.

 

At the front axle level, the air that flows under the camouflaged front wing, will be confronted with another splitter, that is, simultaneously, the leading edge of the Reference Plan.

 

Here, part of the air flow will be aspirated by the front wing’s diffuser, and will flow over the splitter, in order to be drained out by the louvers opened on the lateral walls of the side pods, or to be deviated to cool the radiators and the turbo air exchangers, positioned in tandem, on both side pods, with the radiators leading (drawings 2 and 5).

 

The other part of the air will flow under the splitter, under the Reference Plan and the “skid block”, to be accelerated, immediately in front of the rear diffuser, on the throat of the Venturi Tunnel created between the under floor car surface and the track, by the suction effect produced by the rear diffuser over the air that flows in this area (drawings 2 and 6).

 

We can, also, note that the round edges that joint the under floor with the lateral face of the side pods, will allow the air that flows along the lowest part of this vertical wall, to be suctioned, to the under car, by the rear diffuser, to increase it’s efficiency and the downforce generated and applied over the rear axle of the car.

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Bugatti, History and Renaissance - Prologue

by

Antonio Eiras

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