Accession Number : AD0646989

Title :   A STUDY OF THE STRUCTURE OF THE TURBULENT BOUNDARY LAYER WITH AND WITHOUT LONGITUDINAL PRESSURE GRADIENTS,

Corporate Author : STANFORD UNIV CALIF THERMOSCIENCES DIV

Personal Author(s) : Schraub,F. A. ; Kline,S. J.

Report Date : MAR 1965

Pagination or Media Count : 180

Abstract : The existence of three regions of the turbulent boundary layer, each correlating with a distinct part of the non-dimensional mean velocity profile, was confirmed; these are: (a) wake or intermittent region (b) fully turbulent region (c) wall layer region. Details of the flow structure of these regions were further verified using a new hot-wire anemometer and an improved combined-time-streak marker hydrogen-bubble technique. Instantaneous spanwise velocity profiles over a large extent of the flow at many fixed y-positions across the layer were obtained. The study of the flow structure was extended to include both positive and negative pressure gradient flows, including a relaminarization flow. The hot-wire anemometer provided a means of obtaining detailed mean velocity profiles well within the sublayer region. The hydrogen-bubble combined-time streak marker visualization technique was shown to be a useful tool for quantitative measurement of time-dependent velocity fields. (Author)

Descriptors :   (*TURBULENT BOUNDARY LAYER, FLOW FIELDS), PRESSURE, ANEMOMETERS, FLOW VISUALIZATION, VELOCITY, BUBBLES, HYDROGEN, WAKE

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE