Experimental Study of the Fluid Mechanics of Unsteady Turbulent Boundary Layers.
Abstract
An experimental study of the effects of forced, free-stream unsteadiness on turbulent boundary layers was undertaken in an effort to characterize the nature of such flows and to provide guidance for turbulence modelers. A turbulent boundary layer, which had developed under steady, constant-pressure conditions, was locally subjected to a range of frequencies of sinusoidal free-stream unsteadiness. The response of the boundary layer to these free-stream effects was studied through simultaneous measurements of the u and v components of the velocity field, using a two-color laser-doppler anemometer. To focus on the distinct behaviors of the deterministic and time-averaged fields of flow, the equations of fluid motion were reformulated according to a triple decomposition of velocity and pressure into; (i) a time-averaged measure, (ii) a deterministic or organized, unsteady measure, and (iii) a turbulent measure.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1987
- Accession Number
- ADA184856
Entities
People
- G. J. Brereton
- William C. Reynolds
Organizations
- Stanford University