AIRCRAFT VORTEX WAKE DECAY NEAR THE GROUND

A multi-faceted experimental and analytical research program was carried out to explore the details of aircraft wake vortex breakdown under conditions representative of those which would prevail at low altitudes in the vicinity of airports. Three separate approaches were taken simultaneously. Flight tests with Lockheed L-18 Lodestar and Boeing 747 aircraft flying over ground-based instrumentation provided data on overall vortex behavior, on the vortex ages at the time of onset of instabilities, and on the changes in the vortex velocity fields which resulted from vortex breakdowns. Analytical work on stability theories identified conditions under which vortices could undergo unstable decay. Experimental tests in a water tank looked at the internal instability of vortices, and also shed light on vortex motion near the ground. Finally, a heuristic modeling approach resulted in a simple representation of the relationship between the times of vortex breakdowns and the ambient turbulence levels.

• Supplemental Notes:
  • Prepared in cooperation with Poseidon Research, Los Angeles, Calif.
• Corporate Authors:

  AeroVironment, Incorporated

  145 Vista Avenue
  Pasadena, CA  United States  91107
• Authors:
  • Tombach, I
  • Lissaman, PBS
  • Mullen, J B
  • BARKER, S J
• Publication Date: 1977-5

Media Info

• Pagination: 158 p.

Subject/Index Terms

• TRT Terms: Aerodynamic stability; Aircraft; Aviation safety; Flight; Flight tests; Ground effect; Heuristic methods; Landing; Rolling; Transport properties (Physics); Turbulence; Vortices; Wakes
• Uncontrolled Terms: Transport properties
• Old TRIS Terms: Aircraft landing; Decay schemes; Roll
• Subject Areas: Aviation; Vehicles and Equipment;

Filing Info

• Accession Number: 00166423
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: AV-FR-668, FAA-RD-77-46
• Contract Numbers: DOT-TSC-1008
• Files: NTIS
• Created Date: Sep 28 2003 12:00AM