Characteristics of a wake-vortex tracking system based on acoustic refractive scattering

Details

• Creators:
  Burnham, David C.
• Corporate Creators:
  John A. Volpe National Transportation Systems Center (U.S.)
• Subject/TRT Terms:
  • Wakes
  • Flow
  • Vortices
  • Acoustic scattering
  • Scattering
  • Refractive materials
  • Aircraft
  • Tracking systems
  • Mathematical prediction
  • Wake vortices
  More +
• Resource Type:
  Journal
• Geographical Coverage:
  United States
• Abstract:
  The theory of acoustic-ray bending by aircraft-generated vortices is developed in a form convenient for application to a practical vortex tracking system. The maximum scattering angle 0= is proportional to the vortex circulation divided by the average core radius. Since the circulation for commercial jet transports is roughly proportional to the wingspan, the value of 0m depends little on aircraft size but strongly on the ratio of the core size to the wingspan. For landing aircraft 0m , varies from 0.5 to 1.4 rad depending upon the engine placement. A variety of vortex core models are considered which lead to values of 0m between ; 0.2 and 0.9 rad. The capabilities of a pulsed acoustic vortex tracking system depend strongly upon 0m and therefore upon aircraft type. The effects of timing errors, both vortex induced and random, on tracking accuracy are derived. The fundamental differences between refractive scattering and turbulence scattering techniques are described.
• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/9654/dot_9654_DS1.pdf
• File Type:
  [PDF - 108.45 KB]
• Collection(s):
  Volpe Center
• Main Document Checksum:
  urn:sha-512:eaa621691788ad03000fc48729c562465000dd3b2cb1b2205a0dc8b146676c5598c7db4ab7ca6f88e2319e089769a8874af83ed7f97ef23f7e2d0113f1e4036e