PI-SWERL: Photo Gallery

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First PI-SWERL prototype weighed over 200 lbs (90 kg) and required a large field cart for transporting up to four car batteries.  PI-SWERL prototype in early field testing With the assistance of Rick Purcell, a mechanical engineer at DRI, it was possible to redesign the PI-SWERL (left) that weighed only 30% of the first prototype (right), but was equal in performance. This version used lead shots sewn into a long tube (“snake”) to weigh down the seal between the cylindrical chamber and the test surface.
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Paper strips mounted onto a foam surface with pins were used as flags to demonstrate the swirling nature of the air flow inside the PI-SWERL chamber.  Testing of a miniature version of the PI-SWERL started in 2005. The standalone design shown was abandoned because the battery capacity in this configuration was limited. After several revisions, the current version of the miniature PI-SWERL utilizes a field cart that serves to transport the instrument and all supporting components with little effort.
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Large PI-SWERL mounted onto ATV to facilitate traveling between sites at the Salton Sea in California. Miniature PI-SWERL used to measure the changes in dust emissions after a prescribed fire near Ely, Nevada. Dust emissions are measured at coastal dunes near San Luis Obispo in California
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Test apparatus used to relate the rate of PI-SWERL blade rotation to the amount of wind shear created. Air speed and shearing stress contours obtained with a 2-D hot-wire anemometer