Reactive Aerodynamics (MCN article, 2005)

REACTIVE AERODYNAMICS

Fairings of the future...

Firms test ‘intelligent’ bodywork that will automatically adapt itself to your riding

By Dan Tye

FORGET plain old plastic fairings and fixed windscreens the next step in bike evolution will come from automatically moving panels fitted to bikes to make them turn faster and be more stable.
Secret plans by Yamaha and Honda to examine the technologies are well underway. Honda has already carried out research into placing aerofoils into the tail unit of the FireBlade to increase the downforce on the rear tyre.
Yamaha's Jiro Izaki, the man behind such landmark motorcycles as the R7 and R 1, is also interested in the emerging technology: He said: "Aerodynamics is always something we need to be thinking of. I am very interested in how aircraft use the air moving around them to make them work better. A motorcycle could use the air in a similar way; it would mean many good things for riding quickly on a bike."
The plans centre around a bike's bodywork 'reacting' to the airflow as you ride areas under review include side panels that pop out to aid braking, wings that give downforce to get you around a corner faster and tiny tabs which act like an aircraft's aileron flaps to drag more air on to a bike and make it turn more easily. The new ideas are set to revolutionise the way bikes look.
The ideas are being worked on by a secret Yamaha research and development team working in MotoGP. And although so called proactive aerodynamics are banned by current regulations, designers are still looking at ways of using wind forces to aid a motorcycle's abilities on the track.
MCN asked Barry Ward, chief designer for Team Roberts, whether we're likely to see such aerodynamic features on road going bikes. He replied: "I don't see why it can't be done. It comes down to whether any power systems to move the panels would add weight to the bike. You can use flexible systems, similar to the wings on current F1 cars, which react to the airflow, but it will depend on race rules."
The approach to fairing design is already evolving, from calculating the aerodynamic drag on a shape to actively manipulating the airflow to achieve the best aerodynamic effect for different riding positions.
Although this technology is unlikely to appear on road bikes for several years, Kawasaki toyed with the idea at the Milan Bike Show in 2003. Its ZZR X concept bike had aerofoils that lifted from the bodywork to boost straight line stability and featured motors which moved parts of the bike to give different riding positions.

AIRCRAFT & DEFENCE TECHNOLOGY LEADING THE WAY

A company currently taking reactive aerodynamics further is SAENG (Surface Aeronautics Engineering) which has created add on devices to eliminate noise and turbulence by altering the airflow around the bike. Researchers at the University of California have 1 also created flow control 'microtabs'. These tabs are less than a millimetre in size and can retract and extend to modify the lift on aircraft wings,
A spokesman for SAENG said: "The technology could easily be used for cars and motorcycles the only current limitation is one of overall weight, but we're working on systems that are becoming lighter and more dynamically reactive all the time."
A similar development is an 'Adaptive Virtual Aerosurface' being worked on by the Georgia Institute of Technology. This uses a surface texture to create tiny air swirls that have the effect
of speeding up the flow of air.
Shape changing 'smart' materials could also be used in the future to modify bike fairings. The Defence Advanced Research Project Agency (DARPA) is studying 'nastic' materials that recreate the type of movements similar to plants moving towards sunlight!