Accession Number : AD0754987

Title :   Dreidimensionale Stoerungen in der Grenzschict an einer Konkaven Wand (Three-Dimensional Disturbances in the Boundary Layer Along a Concave Wall),

Corporate Author : DEUTSCHE FORSCHUNGS- UND VERSUCHSANSTALT FUER LUFT- UND RAUMFAHRT E V FREIBURG IM BREISGAU (WEST GERMANY)

Personal Author(s) : Bippes,H. ; Goertler,H.

Report Date : 09 NOV 1971

Pagination or Media Count : 18

Abstract : The development of three-dimensional disturbances in the boundary layer along a concave wall was studied experimentally. Measurements of velocity distributions in the unstable boundary layer and of the amplification of small, forced, initial disturbances were made by photogrammetric evaluation of stereo-photographs. The flow was made visible by the hydrogen-bubble method. A comparison is made with the linearized theory. In the nonlinear part of the amplification, a secondary instability has been observed occurring in the longitudinal zones of low velocity U. A meandering motion ultimately leads to the laminar-to-turbulent transition. (Author)

Descriptors :   (*LAMINAR BOUNDARY LAYER, STABILITY), (*WALLS, CURVED PROFILES), THREE DIMENSIONAL FLOW, PERTURBATION THEORY, BUBBLES, FLOW VISUALIZATION, BOUNDARY LAYER TRANSITION, VELOCITY, WEST GERMANY

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE