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Title:Effects of surface corrugation on primary instability modes in wall bound shear flows
Author(s):Riahi, Daniel N.
Subject(s):Surface Corrugation
Primary Instability Modes
Wall Bounded Shear Flows
Abstract:A general theory for the effects of boundary corrugation on primary instability modes in wall bounded shear flows is developed for cases where either stationary or nonstationary disturbances, arising from discrete or continuous spectrum of primary modes, are the most critical ones near the onset of the primary instability of shear flows. Depending on the type of the critical disturbances, particular corrugations with certain magnitudes and shapes of their amplitudes and with certain magnitudes and directions of their wave number vectors can be most effective leading to the preference of either single or multi-modal forms of the primary disturbances with multiple scales. For discrete modal disturbances, the resulting steady or slowly oscillating stable basic flow can exhibit rolls or non-regular rectangular patterns, or multiple of such patterns for the cases where the stationary disturbances are the most critical ones. For the cases where the non-stationary disturbances are the most critical ones, the preferred oscillatory stable basic flow can exhibit patterns in the form of rolls, non-regular rectangles, non-regular polygons, or multiple of such patterns. For disturbances with continuous spectrum of modes, the resulting preferred flow patterns can be quite unusual and non-regular and, in particular, can exhibit non-periouicity in the streamwise and in the spanwise directions.
Issue Date:1996-08
Publisher:Department of Theoretical and Applied Mechanics. College of Engineering. University of Illinois at Urbana-Champaign
Series/Report:TAM R 831
Genre:Technical Report
Rights Information:Copyright 1996 Board of Trustees of the University of Illinois
Date Available in IDEALS:2021-11-04

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  • Technical Reports - Theoretical and Applied Mechanics (TAM)
    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.

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