Three-Dimensional, Transonic Rotor Flow Field Reconstructed from Holographic Interferogram Data.

Abstract

Holographic interferometry and computer-assisted tomography (CAT) are used to determine the transonic flow field of a model rotor blade in hover. A pulsed ruby laser recorded 40 interferograms with a 61 cm-diam view field near the model rotor-blade tip operating at a tipo Mach number of 0.90. After digitizing the interferograms and extracting fringe-order functions, the data are transferred to a CAT code. The CAT code then calculates pressure coefficients in several planes above the blade surface. The values from the holography-CAT method compare favorably with previously obtained numerical computations and laser velocimeter measurements at most locations near the blade tip. The results demonstrate the techniques's potential for three-dimensional transonic rotor flow studies. Keywords: Holographic interferometry; Computer assisted tomography; Helicopter aerodynamics; Transonic aerodynamics.

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Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1985
Accession Number
ADA160902

Entities

People

  • F. Becker
  • J. K. Kittleson
  • Y. H. Yu

Organizations

  • Ames Research Center

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Army Aviation
  • Blade Tips
  • Boundary Layer
  • Flow Fields
  • Helicopter Rotors
  • Helicopters
  • Image Processing
  • Laser Beams
  • Laser Velocimeters
  • Mach Number
  • Measurement
  • Photographic Film
  • Recording Systems
  • Test Facilities
  • Three Dimensional
  • Two Dimensional
  • Velocimeters

Fields of Study

  • Physics

Readers

  • Aerodynamics.
  • Image Processing and Computer Vision.
  • Optical Physics and Photonics.

Technology Areas

  • Directed Energy