Accession Number:

ADA179976

Title:

Tomographic Reconstruction of Three-Dimensional Flow Over Airfoils.

Descriptive Note:

Final rept. 15 Mar 83-14 Nov 86,

Corporate Author:

SPECTRON DEVELOPMENT LABS INC COSTA MESA CA

Report Date:

1987-03-18

Pagination or Media Count:

31.0

Abstract:

Application of holographic tomography to the flow around the tip of a revolving airfoil is investigated. Data in the form of interferograms obtained at forty different angles obtained by AVRADCOM at NASA Ames were used to reconstruct the three-dimensional density field. An automated fringe analysis capability was developed to digitize, filter and repair the fringe patterns. The binary images of the interferograms were used as the input data to the reconstruction code. A new ART code based on the iterative refinement method of least squares solution was developed for tomographic reconstruction. Solutions were obtained for the density and velocity field at various heights above the blade. An important feature of the technique was found to be that with limited resolution say 20 x 20, it was possible to repeatedly use the same code and zoom into regions surrounding important features of the flow and, hence, reconstruct the flow field in greater detail. This feature was used and the position of the shock wave over the wing was determined. Author

Subject Categories:

  • Fluid Mechanics
  • Holography
  • Cybernetics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE