Résumé | Over the period 2006 to 2012, the NRC enroute wake vortex flight research project has measured vortex core profiles and properties, during numerous traverses of the vortex cores generated by Heavy and Super Category jet transports, flying enroute in cruise. The vortex core traverses were conducted by the NRC T-33 and were all initiated in-trail, with the T-33 flight-path being parallel to the vortex core axis generally vortex core entries were made in the vortex core six o-clock position. Core traverses took 3/4 to 11/4 seconds, over which the T-33 flew along the vortex axis a distance of 200-300 metres, and 4-20 m across the cores, amounting to traverse angles of 2-4° The vortex core profile symmetry and/or constancy over such a small traverse angle was ascertained, by comparing the advancing and retreating segments (to the closest point-of-approach, CPA) of the profiles. Often the implied symmetry/constancy was good, sometimes it wasn't small, very energetic secondary and tertiary vortex segments were encountered only to or from the CPA, on either the advancing or retreating segment only. In particular, they made identification of vortex core funnel segments difficult. In 2011, yaw traverses of vortex cores were conducted, entering the cores at angles of yaw to the vortex axial direction, of 1530° and/or angles of pitch of c.5° so that the cores were traversed over much smaller axial distances than intrail traverses. The analyses of the flight data from these yaw core-traverses is presented. © 2012 by The Crown in Right of Canada. Published by the American Institute of Aeronautics and Astronautics, Inc. |
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