Natural Unsteadiness of a Separation Bubble behind a Backward-Facing Step,
Abstract
Low-frequency unsteadiness of a reattaching shear layer was studied in subsonic flow behind a backward-facing step. Power spectra of streamwise velocity fluctuations were measured using a hotwire probe. Spectra measured near the centerline of the separated shear layer showed that a substantial fraction of the measured turbulence intensity occurs at frequencies significantly lower than the large-eddy passing frequency. The strong low-large-eddy passing frequency. The strong low-frequency contribution is not present in the upstream boundary layer or in the reattached shear layer. It was concluded that the low-frequency energy is caused by a non-periodic vertical motion of the separated shear layer. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1984
- Accession Number
- ADP004176
Entities
People
- A. E. Alving
- John K. Eaton
Organizations
- Stanford University