Accession Number : AD0663264

Title :   PERIODIC BOUNDARY LAYER FLOWS OVER A FLAT PLATE. PART III: WITH DISTURBANCE BARS.

Descriptive Note : Technical memo.,

Corporate Author : JOHNS HOPKINS UNIV SILVER SPRING MD APPLIED PHYSICS LAB

Personal Author(s) : O'Brien,V.

Report Date : AUG 1967

Pagination or Media Count : 108

Abstract : Parallel periodic flows created in viscous fluids by an oscillating flat plate were disturbed by placing bars on the plate. The local regions of nonparallel flow were investigated experimentally using dye and neutral density particles as tracers. The flows were also studied theoretically by numerical solution of the Stokes equation. Though these solutions are approximate (because they neglect the nonlinear inertia term), the calculations show reasonable agreement with the experimental data at small similarity parameter. The changing character of the separated flow with height of the rectangular disturbance bar is clearly indicated. At moderate similarity parameter with large bars, there are discrepancies attributable to the neglected term, while at still higher similarity parameter an intermittency appears that may be related to the stability of these unsteady viscous flows. A number of related flows were also calculated for comparison. (Author)

Descriptors :   (*BOUNDARY LAYER, *FLAT PLATE MODELS), VORTICES, OSCILLATION, FLOW VISUALIZATION, LAMINAR FLOW, TURBULENCE, NUMERICAL ANALYSIS

Subject Categories : Aerodynamics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE