This thesis presents a method based on the velocity singularities for the analysis of oscillating airfoils. The method of velocity singularities has been originally developed by Mateescu for the analysis of the steady flows past airfoils. This method makes use of special singularities associated to the leading edge and ridges that directly represent the complex perturbation velocity. / Closed form solutions were derived for the pressure distributions and for the aerodynamic forces and moments acting on the oscillating airfoils with or without oscillating ailerons. / The solutions obtained with the velocity singularity method for steady flows past airfoils were found to be in very good agreement with the exact solutions obtained by conformal transformation in the case of thin Joukowski airfoils, as well as with the previous solutions for the case of flexible-membrane airfoils obtained by Mateescu & Newman, Nielsen and Thwaites. / For unsteady flows, this method has been validated for airfoils executing oscillatory motions in translation and pitching rotation and for airfoils with ailerons executing oscillatory rotations. The pressure distributions and the aerodynamic forces and moments obtained with the present method were found to be in excellent agreement with the previous solutions obtained by Theodorsen and Postel and Leppert. / The method has then been extended to the unsteady flows past airfoils executing flexural harmonic oscillations. Closed form solutions were also derived for the pressure distributions and the aerodynamic forces and moments acting on an airfoil with an aileron executing flexural oscillations. No comparisons were presented for the cases of flexural oscillations since there are no previous results known. / The present approach displayed an excellent accuracy and efficiency in all problems studied.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.30233 |
| Date | January 2000 |
| Creators | Abdo, Mohammed. |
| Contributors | Mateescu, Dan (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Engineering (Department of Mechanical Engineering.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001763002, proquestno: MQ64209, Theses scanned by UMI/ProQuest. |
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