Accession Number : ADP005897

Title :   Matched Index Laser Anemometry Systems for Flow Studies in Complex Geometries,

Corporate Author : CASE WESTERN RESERVE UNIV CLEVELAND OH CHEMICAL ENGINEERING DIV

Personal Author(s) : Dybbs, A. ; Edwards, R. V. ; Reshotko, E.

Report Date : JUN 1987

Pagination or Media Count : 18

Abstract : Optical access to the flow is necessary if laser anemometry is to be used to map a given flow field. Often this access is difficult/impossible to obtain because of the shape of the object about which (or within which) the flow exists. Examples are flows in porous media, fluidized beds, heat exchangers or near sinusoidal surfaces. Making the object of transparent material such as of glass or plexiglas is not sufficient to provide a reliable, usable optical environment for laser measurements. It is often necessary to use a fluid whose index or refraction matches that of the object. At the Case Center for Complex Flow Measurements, at Case Western Reserve Univ., we have constructed a matched index of refraction flow system. This paper describes this system and present examples of measurements made with this system. In particular, this paper discusses: (1) When index matching is needed; (2) How close the match has to be; (3) Practical details of operating an index matched facility; and (4) Flow measurements made using an index matched facility to study boundary layer transition due to roughness, the flows within rod bundles and the flow regimes within porous media.

Descriptors :   *FLOW FIELDS, *REFRACTIVE INDEX, MEASUREMENT, LASER APPLICATIONS, FLUIDS, TRANSPARENCE, MATCHING, MATCHING, BOUNDARY LAYER TRANSITION, ROUGHNESS, RODS, POROUS MATERIALS.

Subject Categories : Fluid Mechanics
      Lasers and Masers
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE