A Diagnostic Study of Flow in the Wake of a Circular Disk Using a Photon Correlation Laser Velocimeter.
Abstract
The present investigation involves a diagnostic study of flow in the wake of a circular disk utilizing schlieren photography and a photon correlation laser velocimeter system (LDV). The schlieren system was used to examine the basic flow pattern over a 2.0 inch diameter disk and to establish the bounds of the recirculation zone. In all tests, the flow originated from a 1.5 inch diameter axially symmetric free jet with an exit Mach number of 0.35. The disk was positioned in the flow 12 jet diameters downstream of the exit. Mean velocity and turbulence intensity profiles were measured at selected locations in the near wake region of the 2.0 and a 1.5 inch diameter disk with the LDV system. This was accomplished without particle seeding of the flow. A free jet survey was conducted for comparison with theoretical predictions to analyze the quality of the LDV data. The schlieren system produced high quality photographs from which the dimensions of the recirculation zone were obtained. Mean velocity and turbulence intensity profiles were acquired at the varied stream-wise locations behind each disk with the LDV system. The laser velocimeter system, when used in conjunction with a phase modulator, clearly indentified the flow direction. Bounds of the recirculation zone found from the LDV study agreed with the results of the schlieren study. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1980
- Accession Number
- ADA082167
Entities
People
- Steven L. Morris
Organizations
- Air Force Institute of Technology