THE MOVEMENT, STRUCTURE AND BREAKDOWN OF TRAILING VORTICES FROM A ROTOR BLADE

Abstract

The results of some flow visualisation experiments on the trailing vortices from a model rotor blade are presented. It is found that, at low tip- speed ratios, trailing vortices close to the leading edge of the disc first pass up through the disc before entering the main flow field. At the rear of the disc the vortices maintain a regular pattern relative to each other. The vortices are fully rolled up in about 60 deg of azimuth movement of the blade. Measurements with a hot-wire anemometer show that the vortex core is about one- tenth of a blade chord in diameter, which is consistent with a laminar core state. Outside the core the velocity field is irrotational. Some observations were made of a trailing vortex as it approaches the support pylon. The vortex at first follows the pylon contours and remains a tightly-rolled core, but it ultimately leaves the pylon surface and its structure breaks down, rather like the vortices from the leading edges of a delta wing.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Apr 18, 1967
Accession Number
AD0687168

Entities

People

  • I. A. Simons
  • J. P. Jones
  • R. E. Pacifico

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Aircrafts
  • Blade Tips
  • Boundary Layer
  • Cameras
  • Flow Fields
  • Flow Visualization
  • Fluid Dynamics
  • Fluid Flow
  • Fluid Mechanics
  • Ground Effect
  • Ground Effect Machines
  • Helicopters
  • Hot Wire Anemometers
  • Measurement
  • Mechanical Properties
  • Short Takeoff Aircraft
  • Stratified Fluids

Fields of Study

  • Physics

Readers

  • Aerodynamics.
  • Aerodynamics/Aeronautics.
  • Fluid Mechanics and Fluid Dynamics.