Accession Number : AD0714628

Title :   A Preliminary Experimental Study of the Behavior of Disturbances Introduced into a Highly Accelerated Laminar Boundary Layer.

Descriptive Note : Final rept.,

Corporate Author : AERONAUTICAL RESEARCH ASSOCIATES OF PRINCETON INC N J

Personal Author(s) : Snedeker,Richard S. ; Donaldson,Coleman duP. ; Yates,John E.

Report Date : OCT 1970

Pagination or Media Count : 56

Abstract : An experimental study is described in which the effects of disturbances introduced into a highly accelerated, two-dimensional, laminar boundary layer were investigated. The disturbances were produced by a vibrating ribbon and the Reynolds number was in the range 400 - 1500. Small amplitude disturbances in the frequency range 10 - 150 Hz damped out quickly. For certain types of disturbances, apparent transition was observed even for values of the Reynolds number an order of magnitude below the minimum critical value given by classical theory. Tests were made to determine the nature of this transition, but no specific conclusion was developed on the basis of the available data. Comparison of measured and theoretical damping rates showed reasonable agreement for cases in which no transition occurred. The explanation of the observed effects, and the way in which the concepts of streamtube stretching under the influence of high acceleration is involved, requires further investigation. (Author)

Descriptors :   (*LAMINAR BOUNDARY LAYER, STABILITY), TURBULENT BOUNDARY LAYER, VIBRATION, TURBULENCE, REYNOLDS NUMBER

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE