Accession Number : ADA332283

Title :   Development of High Speed Interferometry Imaging and Analysis Techniques for Compressible Dynamic Stall

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF AERONAUTICS AND ASTRONAUTICS

Personal Author(s) : Chandrasekhara, M. S. ; Carr, L. W. ; Wilder, M. C.

PDF Url : ADA332283

Report Date : SEP 1997

Pagination or Media Count : 13

Abstract : The development of a high speed, phase locked, real time, point diffraction interferometry system for quantitative imaging of unsteady separated flows is described. The system enables recording of up to 224 interferograms of the dynamic stall flow over an oscillating airfoil using a drum camera at rates of up to 40 KHz, controlled by custom designed electronic interlocking circuitry. Several thousand interferograms of the flow have been obtained using this system. A comprehensive image analysis package has been developed for automatic processing of this large number of images. The software has been specifically tuned to address the special characteristics of airfoil flow interferograms. Examples of images obtained using the standard and the high speed interferometry techniques are presented along with a demonstration of the image processing routine's ability to resolve the fine details present in these images.

Descriptors :   *INTERFEROMETRY, *COMPRESSIBLE FLOW, *STALLING, IMAGE PROCESSING, REAL TIME, ROTOR BLADES(ROTARY WINGS), FLOW VISUALIZATION, INTERFEROGRAMS, FLOW FIELDS, UNSTEADY FLOW, FLOW SEPARATION, WIND TUNNELS, ROTATING DRUM CAMERAS.

Subject Categories : Aerodynamics
      Fluid Mechanics
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE