"Cyberspace Wind Tunnel" Analysis of the
Spirit of America Jet-Powered Car
using the EOIS Mini-Moiré Sensor

EOIS recently helped Craig Breedlove solve a problem with the aerodynamics of his Spirit of America jet-powered car (see below). The car had experienced a problem while attempting to break the world land speed record. At 675 mph the car became airborne, and landed on its side, sustaining serious damage. One possible cause of the accident was an aerodynamic problem such as a shock wave or side wind. A wind tunnel test was needed to find out the exact cause of the problem.

A high-tech approach was used to quickly and inexpensively simulate a wind tunnel test. EOIS digitized a model of the car (the original was still being repaired). Then Rocket Science Inc. of Beaverton Oregon used computational fluid dynamics (CFD) to simulate wind tunnel tests of the model. From these tests, he recommended changes to improve the safety of the car.

EOIS used its Mini-Moiré with a portable FaroArm® (see below), so we could travel to the customer site to capture the data. We scanned one side of the model in a few hours, capturing 60 Mpts at a resolution of 0.08mm. The other side of the model was reconstructed using part symmetry.

The data was then reduced to 2 Mpts and exported to an IGS file for the CFD analysis software (see below).

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The combination of the Mini-Moiré sensor and the FaroArm has proven to be a very flexible tool. It is portable and rugged enough to travel to most work sites, and the 7 rotation axes of the arm allow it to to scan even the most complex shapes.