University of Illinois Urbana-Champaign

Nonlinear instabilities of shear flows over rough walls

Riahi, Daniel N.

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https://hdl.handle.net/2142/112527

Description

Title
Nonlinear instabilities of shear flows over rough walls
Author(s)
Riahi, Daniel N.
Issue Date
1996-06
Keyword(s)
  • Shear Flows
  • Rough Walls
  • Nonlinear Instabilities
Abstract
A spectral theory applied to the downstream evolution of nonlinearly interacting waves in a weakly nonparallel shear flow over a rough wall predicts dominant contributions to the nonlinear terms by certain subharmonic components at frequencies and spanwise wave numbers of the flow and at span wise wave numbers of the rough surface shape. The phase function of the waves takes the form of the phase function for the surface roughness shape under significant roughness effects. The theory also determines wave amplitudes, which can depend on the amplitude of the surface roughness. The results depend in a non-trivial way on the relative order of magnitudes of the roughness and wave amplitudes, both of which are assumed to be small.
Publisher
Department of Theoretical and Applied Mechanics. College of Engineering. University of Illinois at Urbana-Champaign
Series/Report Name or Number
  • TAM R 827
  • 1996-6014
ISSN
0073-5264
Type of Resource
text
Language
eng
Permalink
http://hdl.handle.net/2142/112527
Copyright and License Information
Copyright 1996 Board of Trustees of the University of Illinois

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Technical Reports - Theoretical and Applied Mechanics (TAM) PRIMARY
TAM technical reports include manuscripts intended for publication, theses judged to have general interest, notes prepared for short courses, symposia compiled from outstanding undergraduate projects, and reports prepared for research-sponsoring agencies.