Helicopter Blade-Vortex Interaction Locations: Scale-Model Acoustics and Free-Wake Analysis Results.

Abstract

The results of a model rotor acoustic test in the Langley 4- by 7-Meter Tunnel are used to evaluate a free-wake analytical technique. An acoustic triangulation technique is used to locate the position in the rotor disk where the blade-vortex interaction noise originates. These locations, along with results of the rotor free-wake analysis, are used to define the geometry of the blade-vortex interaction noise phenomena as well as to determine if the free-wake analysis is a capable diagnostic tool. Data from tests of two teetering rotor systems are used in these analyses. Keywords; Helicopter rotor disks; Free wake; Blade-vortex interactions; Acoustic properties.

Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1987
Accession Number
ADA179379

Entities

People

  • Danny R. Hoad

Organizations

  • National Aeronautics and Space Administration

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Acoustic Properties
  • Acoustics
  • Aircrafts
  • Airframes
  • Geometry
  • Helicopter Rotors
  • Helicopters
  • Models
  • Navigational Equipment
  • Rotary Wing Aircraft
  • Scale Models
  • Triangulation
  • Vehicles

Fields of Study

  • Physics

Readers

  • Aerodynamics.
  • Fluid Dynamics.