Aircraft Wake Vortex Core Size Measurements

This paper examined data from three aircraft field tests designed to measure the size of the vortex cores generated by the aircraft. The field tests were performed between 1990 and 1997 at Idaho Falls, ID, Wallops Island, VA, and John F. Kennedy International Airport (JFK) in NY. At Idaho Falls, an instrumented 200-foot tower was used to measure velocities in the wakes of Boeing 727, 757 and 767 aircraft flown upwind of the tower. In the Wallops Island test, velocities and smoke trails behind a Lockheed-Martin C-130 aircraft were measured by an instrumented North-American Rockwell OV-10 aircraft flown behind the C-130. For the JFK tests, the vortex wakes of landing aircraft were measured by a Continuous Wave lidar operated by MIT/Lincoln Laboratories. The results from all three field tests are quite consistent and suggest that the size of the velocity cores in trailing vortices behind an aircraft is on the order of one percent of the wingspan of the aircraft, where core size is defined as the radial distance from the vortex center to the point of maximum tangential velocity. The authors note that numerical simulations of trailing vortex evolution typically use velocity vortex core sizes in the range from five to twelve percent of the wingspan of an aircraft. Therefore, the values of velocity core size used in numerical models are significantly larger than the full-scale values reported here. The authors also show that a typical size of smoke trails, where smoke is used to visualize the vortices behind an aircraft, is approximately twice the size of the velocity core.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References;
  • Pagination: 10p

Subject/Index Terms

Filing Info

  • Accession Number: 01475585
  • Record Type: Publication
  • Files: NTL, TRIS
  • Created Date: Mar 14 2013 12:46PM