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Courtesy of Advantage CFD
Motorbike with flow path lines
An innovative approach to capturing the geometry of a moving motorcycle
and rider in position for a 3D CFD analysis has been successfully carried
out by Advantage CFD with the help of 3D Scanners Limited. This so-called
"reverse engineering" of a motorcycle and rider was the brainchild
of Dr. Rob Lewis of Advantage CFD, a Division of Reynard Motorsport, in
Northamptonshire, England. The analysis was carried out in an attempt
to convince performance bike teams that CFD can play a major role in race
bike design and aerodynamic performance, using a process widely used by
their four-wheeled counterparts.
Advantage CFD engineers approached 3D Scanners in Coventry, England,
to scan a complete Yamaha R1 and rider in a cornering position of approximately
45 degrees, doing a 500m radius corner at a velocity of 150 mph (67 m/s).
The engineers at 3D Scanners generated a 3D point cloud of the geometry
in less than a day, from which an accurate CAD model was developed. This
was used to develop a hybrid mesh for the CFD analysis. The CFD predictions
for the cornering bike suggested that the lean angle is not significantly
affected by the magnitude of the aerodynamic force normal to the vertical
plane of the motorcycle. Visualization of these initial results indicated
that improving the fairing design of the bike to create a more effective
venturi could increase the lateral force and hence the cornering speed.
A revised fairing was designed in-house that reduced lift and increased
the side-force which resulted in a cornering speed-up of approximately
0.5 mph. This was achieved without a significant increase in drag.
Lewis is very confident that, in time, CFD will become an essential tool
in analyses of two-wheeled sport bikes. "We have already been able
to recommend design changes to bike companies and it is conceivable that
the work we have been doing may even bring radical changes to the way
motorbikes are designed" he said.
For more information: 3D scanners:
www.3dscanners.co.uk
Advantage CFD:
www.advantage-cfd.co.uk
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