Concerning the Interaction of Non-stationary Cross-Flow Vortices in a Three-Dimensional Boundary Layer

Abstract

Recently there has been much work devoted to considering some of the many and varied interaction mechanisms which may be operative in part of three- dimensional boundary layer flows, here are concern resonant triads of crossflow vortices. In contrast to previous work the effects of interactions upon resonant triads are examined with each member of the triad has the property of being linearly neutrally stable; then the importance of the interplay between modes can be relatively easily assessed. Investigating modes within the boundary layer flow above a rotating disc; this choice is motivated by the similarity between this disc flow and many important practical flows and, secondly, our selected flow is an exact solution of the Navier-Stokes equations which makes its theoretical analysis especially attractive. The desired triads of linearly neutrally stable modes can exist within the chosen boundary layer flow and then subsequently obtain evolution equations to describe the development of the amplitudes of these modes once the interaction mechanism is accounted for. The coefficients of the interaction terms within the evolution equations are, the general, given by quite intricate expressions although some elementary numerical work shows that the evaluation of these coefficients is practicable. The basis of this work lends itself to generalization to more complicated boundary layers and effects of detuning or non-parallelism could be provided for within the asymptotic framework.

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Document Details

Document Type
Technical Report
Publication Date
May 01, 1990
Accession Number
ADA227234

Entities

People

  • Andrew P. Bassom
  • Philip Hall

Tags

Communities of Interest

  • Counter IED
  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Boundary Layer
  • Boundary Layer Flow
  • Computational Fluid Dynamics
  • Computational Science
  • Contracts
  • Cross Flow
  • Equations
  • Fluid Dynamics
  • Fluid Flow
  • Fluid Mechanics
  • Frequency
  • Geometry
  • Integrals
  • Navier Stokes Equations
  • Reynolds Number
  • Thickness
  • Three Dimensional

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Fluid Mechanics and Fluid Dynamics.
  • Systems Analysis and Design