Stability of the Flow Around a Cylinder: The Spin-Up Problem

Abstract

Our concern is with the flow around an infinite cylinder, which at a certain instant is impulsively started to spin. The growth of vortices in the resulting boundary layer occurring outside the cylinder is investigated. This layer is essentially a Rayleigh layer which grows with time, so the mechanism involved is similar to that studied in Hall (1983). Vortices with wavenumber comparable to the layer thickness are shown to be described by partial differential equations that govern the system numerically. We assume that the Rayleigh layer is thin so particles are confined to move in a path with radius of curvature the same as the cylinder. The Goertler number is a function of time, so we consider the time scale which produces an order one Goertler number. We consider the right hand branch calculation by letting the time tend to infinity. Inviscid Goertler modes are also considered.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1991
Accession Number
ADA242160

Entities

People

  • S. R. Otto

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Boundary Layer
  • Computational Fluid Dynamics
  • Differential Equations
  • Engineering
  • Equations
  • Flow
  • Flow Fields
  • Fluid Dynamics
  • Fluid Flow
  • Fluid Mechanics
  • Geometry
  • Layers
  • Mathematics
  • Mechanical Properties
  • Mechanics
  • Reynolds Number
  • Stratified Fluids

Fields of Study

  • Mathematics

Readers

  • Fluid Dynamics.
  • Fluid Mechanics and Fluid Dynamics.