Accession Number:

ADA184856

Title:

Experimental Study of the Fluid Mechanics of Unsteady Turbulent Boundary Layers.

Descriptive Note:

Final rept. 3 Jul 83-6 Jan 86,

Corporate Author:

STANFORD UNIV CA THERMOSCIENCES DIV

Personal Author(s):

Report Date:

1987-05-01

Pagination or Media Count:

258.0

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.

Subject Categories:

  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE