Thursday, July 29, 2010

Aeroelasticity in F1

Formula One's latest technical controversy surrounds the aeroelastic front wings currently used by Red Bull and Ferrari. The ends of the front wings on these cars appear to be deforming at high aerodynamic loadings, thereby generating ground effect downforce. Courtesy of Darren Heath's photographs, estimates suggest that the front-wing endplates are deflecting by up to 24mm.

McLaren, in particular, are currently working hard to understand how the effect is achieved. A cursory literature search, however, suggests that the effect probably depends upon the orientation of the carbon-fibre plies in the front wing, and Red Bull and Ferrari may even be using a method of coupling the bending of the front wing to the twisting of the endplates.

City University's Aeronautics department point to research revealing "the effect of ply orientation on the dynamic and aeroelastic behaviour of composite wings." Bristol University's Aerospace Engineering department provides further details, explaining that "Laminated composite materials designed adequately can present elastic coupling properties that can be used to induce an adaptive change. For instance, a composite presenting in-plane elastic coupling that is loaded under normal loads experiences a shear deformation. The proposed morphing design consists of a wing made of laminated composite materials presenting elastic couplings so as to induce twist when the wing bends. This concept, if proven, could provide a passive actuation for the control of the wing twist." Elsewhere, there are claims that "most new helicopters have composite elements in the hub/root of the main blades that are used to replace functions usually done by hinges on older designs."

Fascinatingly, a group of researchers in the Netherlands have also just published a paper entitled 'Aeroelastic tailoring using lamination parameters - Drag reduction of a Formula One rear wing', which also proposes a bending-torsion coupling, in this case to reduce rear-wing induced drag.

If these front wing effects are genuinely dependent upon the precise orientation of the carbon-fibre plies, then it will be interesting to see if McLaren can react on a time-scale consistent with winning this year's World Championship...

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