Blackbird Cart Travels Into Wind Faster Than The Wind
Blackbird cart travels upwind faster than the wind using only the kinetic energy in the air...
A kitesurfer, paraglider and aerodynamicist has shown that it’s possible to travel upwind faster than the wind itself, using only the kinetic energy in the circulating air.
The specially modified cart, called the Blackbird, took the runway at the New Jerusalem Airport, Tracy, California, where it clocked a top speed 2.1 times faster than the upwind.
“For some folks, the idea that it can advance directly into the wind at all has been counter-intuitive,” said Rick Cavallaro, the pioneering member of the Blackbird team.
Image Credit: Rick Cavallaro, 2012.
The Blackbird Cart Travels Upwind Faster Than The Wind
However, by utilizing the same principles as sailing boats, it is indeed possible to use the air’s kinetic energy to travel into the wind. In fact this technique is not nearly as controversial as travelling downwind faster than the wind – a feat that Cavallaro also proved is possible.
The Blackbird cart was originally configured to use the air’s kinetic energy to travel downwind, and was able to reach speeds 2.8 times faster than the wind when doing so.
So, when it comes to harnessing the power of the wind to travel upwind, could it be possible for a vehicle heading into the wind to travel faster and faster in an endless feedback loop? Unfortunately that’s appears to be impossible as Cavallaro explains:
“There’s at least an element of truth to this, but as with the downwind cart, frictional losses still win out at a certain speed.”
Since the Blackbird cart was originally configured to power downwind, Cavallaro had to reverse the whole system to make the cart travel upwind.
In order to work more like a sail boat, the Blackbird uses two turbine blades that spin round on a common axis to propel the cart forward into the wind and crosswind as the blades turn around the axis.” Cavallaro explains:
“This combination of upwind and cross-wind motion is identical to that of a sail on a boat on an upwind tack…
“Where the sailboat has a keel to constrain the motion of the sail in the correct direction, we have a transmission and wheels that perform the same job.”
Cavallaro also had to take into account the Blackbird’s unique design – to prevent the turbine’s torque from flipping the vehicle over, one of its axles is longer than the other. This meant that Cavallaro had to reconfigure the chain drive to fit the asymmetrical axle.
With his new milestones set, Cavallaro is now hoping to see other aerodynamic enthusiasts making similar developments. “I would like to see both our upwind and downwind records broken – regularly,” he said.
- Keith Barry: Wind-Powered Vehicle Can Also Travel Upwind Faster Than the Wind. Wired, 07/11/2012.