The Higher-Harmonic Control Aeroacoustic Rotor Test (HART) in the DNW-LLF

Abstract

With increasing use of helicopters the problem of noise emission of helicopters became more and more important. The first HART program on rotorcraft noise has shown that blade vortex interaction (BVI) is a major source of impulsive noise. As BVI-noise is generated by the induced velocities of tip vortices, it depends on vortex strength and miss-distance, which itself depends on vortex location and orientation and convection speed relative to the path of the advancing blade. The detailed study of these vortices by means of Particle Image Velocimetry (PIV) and by means of flow visualization with the Laser Light Sheet method (LLS) is of particular interest for progress towards quieter rotorcraft and is the subject of this program. For a detailed analysis of blade vortex interaction it is also essential to gain some knowledge about the deformation of the rotor blades due to aerodynamic loading at different azimuth angles. For this purpose DNW developed a dedicated photonical method to evaluate blade deflection during operation of the rotor.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 2000
Accession Number
ADA389689

Entities

People

  • E. Merker
  • G. Lehmann
  • K. Pengel

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Cameras
  • Flow
  • Flow Visualization
  • Fluid Mechanics
  • Helicopter Rotors
  • Image Processing
  • Images
  • Lasers
  • Light Pulses
  • Light Sources
  • Measurement
  • Mechanical Phenomena
  • Particle Image Velocimetry
  • Stratified Fluids
  • Two Dimensional
  • Video Images
  • Wind Tunnels

Fields of Study

  • Physics

Readers

  • Acoustics.
  • Aerodynamics.

Technology Areas

  • Directed Energy