Source:
http://www.dpncanada.com/
http://www.dpncanada.com/...;id=949&Itemid=2
Human-powered Vehical Claims 24-hour Record
A Canadian designer has used SolidWorks and COSMOS software (solidworks.com) to develop and optimize a human-powered vehicle that claimed the 24-hour distance record in July. Capable of more than 60 mph, the machine is essentially a recumbent bicycle – one where the rider lies on his back – encapsulated in an aerodynamic carbon fiber fairing.
The “Critical Power” resembles an eight-foot long bullet and was the pilot’s mobile home during the record attempt. Greg Kolodziejzyk, a top 10 age-group finisher in several Ironman triathlons, broke the 11-year-old record of 1,021.36km in July, traveling 1046.94 km. The retired computer-imaging entrepreneur chose the Redwood Acres Motor Speedway in Eureka, CA, as his venue after evaluating 19 other tracks in North America for climate, surface and layout.
“SolidWorks and COSMOS software helped us develop what we are convinced is a superior design from aerodynamic, mechanical, and ergonomic standpoints,” said designer Ben Eadie, owner of MountainWave Design Services in Calgary (mountainwave.com), before the attempt. “But the proof will be laid down on the track.”
Eadie optimized the vehicle’s aerodynamics by creating a “virtual wind tunnel” with COSMOSFloWorks computational fluid dynamics analysis software. He accomplished this by calibrating COSMOSFloWorks settings for turbulence, relative density, percentage error, and interactive elements with the solid body. After testing a series of established human-powered vehicle designs, he settled on an entirely new design that tapers to a thin vertical wedge in the stern. This shape serves to part the air and gently reassemble it with minimal turbulence.
The vehicle’s shape resembles that of a fish. “We didn’t start out thinking ‘fish,’ but when my designs follow nature, I always feel like I’m headed in the right direction,” said Eadie. “Natural selection is probably the best design optimization process you can hope for.” The virtual wind tunnel’s findings correlated by more than 98% with calculations experienced on the track.
COSMOSWorks analysis software helped Eadie determine the amount of carbon fibre required for the shell design. It graphically highlighted hot spots that needed reinforcement and cold spots where a layer or two of fiber could safely be removed.
Eadie started the design process two and a half years ago with a photograph of Kolodziejzyk in a position that leveraged the powerful pedal stroke the triathlete had refined over thousands of miles of training. Eadie superimposed the photo onto a SolidWorks drawing, resulting in an ultra-efficient design allowing only single millimeters of clearance in all directions. The bike literally fits like a glove.
Eadie has used SolidWorks software since 1999 to develop the Critical Power as well as more traditional recumbent bicycles and special projects ranging from hydrogen fuel cells to diaper-changing tables. “With every release SolidWorks continues to prove why it is the most robust 3D CAD tool for designing better products, whether in carbon fibre, structural steel, plastics, or sheet metal,” Eadie said.
Added Kolodziejzyk, “I don’t know where SolidWorks and COSMOS leave off and where Ben’s expertise begins, but the machine is fast.”
For more information on the record attempt, visit Kolodziejzyk’s Web site at http://www.adventuresofgreg.com/HPVMain.html.