Measurement of Wake Vortex Strength by Means of Acoustic Back Scattering

Details

• Creators:
  Burnham, David C. ; Sullivan, Thomas E. ; Wilk, Leonard S.
• Corporate Creators:
  John A. Volpe National Transportation Systems Center (U.S.) ; Massachusetts Institute of Technology
• Subject/TRT Terms:
  • Wakes
  • Vortices
  • Airports
  • Acoustic measuring instruments
  • Velocity measurement
  • Flow measurement
  • Data collection
• Resource Type:
  Journal Article
• Corporate Publisher:
  American Institute of Aeronautics and Astronautics
• Abstract:
  A simple acoustic sounder is shown to produce reliable velocity profiles of aircraft wakes at altitudes below 50 m. Data collection during normal airport landing operations was feasible because the sensor does not intrude into the airspace being measured. A spatial scan through the wake is obtained when the ambient wind transports the wake through the sounder beam. The characteristics of the scattered signals and their spectral densities are presented as intensity modulated CRT displays termed "Acoustograms." The data are processed to yield the radial dependence of the velocity and circulation in the wake vortices. The circulation data are fitted to a simple model with two parameters: strength and core radius. The spatial and velocity resolution of the sounder is adequate to measure vortex strength but not to probe details of the core structure. Reliable measurements using this technique are possible only when the vortex transport velocity is well-defined.
• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/34196/dot_34196_DS1.pdf
• File Type:
  [PDF - 108.46 KB]
• Collection(s):
  Volpe Center
• Main Document Checksum:
  urn:sha-512:cdcf3b02a56187b44a31a8e6876985a32f8acf60fef99eeed2b3af386b155b26fe3e5abf8b3e24c0ecf27d7adddf522d74bb96121a96bc2dc95df2c26d461e6d