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Virginia Tech

On subharmonic instability in boundary layers

Abstract

dc:description.abstract

The subharmonic instability in two-dimensional boundary layer on a flat plate is analyzed using the parametric instability model and the resonant triad model. The problems arising from both models are solved numerically using the shooting technique and results are presented. It is found that in the presence of a strong interaction (e.g., large amplitude of the two-dimensional wave), results from the resonant triad model are inaccurate as compared with the experimental data and the t results from the parametric instability model. This is mainly because the resonant triad model is a weakly nonlinear model, and it does not account for the modification of the eigenfunctions of the interacting waves which really takes place as we find out from the experiments. The parametric instability model is a powerful model, despite all the assumptions included. The model, however, does not introduce a clear understanding of how the subharmonic mode originates from the three-dimensional Tollmien-Schlichting modes. For a weak interaction results from the resonant triad model and the parametric instability model get close to each other.

Degree

thesis:*
Name thesis:degree_name
Master of Science
Level thesis:degree_level
masters
Discipline thesis:degree_discipline
Engineering Mechanics
Department dc:contributor.department
Engineering Mechanics
Grantor dc:publisher
Virginia Tech
Year dc:date.issued
1987

Author and committee

dc:creator, dc:contributor.*
Author dc:creator
  • Masad, Jamal A.
Chair dc:contributor.committeechair
  • Nayfeh, Ali H.
Committee members dc:contributor.committeemember
  • Mook, Dean T.
  • Ragab, Saad A.

Rights

dc:rights
Statement dc:rights
  • In Copyright

Identifiers

dc:identifier.*
Dc Identifier Other
etd-11172012-040114
OAI identifier oai:identifier
oai:vtechworks.lib.vt.edu:10919/45783

Chain of custody

source
Harvested from
Virginia Tech
Base URL
vtechworks.lib.vt.edu/oai/request
Last updated
2026-07-22
Source record
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citation

Masad, Jamal A.. On subharmonic instability in boundary layers. masters thesis, Virginia Tech, 1987. http://hdl.handle.net/10919/45783