ANALYSIS OF AN OSCILLATING JOUKOWSKI AIRFOIL WITH SURFACE SUCTION ANDMOVING VORTICES

Authors
Citation
Cs. Chiu, ANALYSIS OF AN OSCILLATING JOUKOWSKI AIRFOIL WITH SURFACE SUCTION ANDMOVING VORTICES, Journal of aircraft, 31(5), 1994, pp. 1050-1056
Citations number
NO
Categorie Soggetti
Aerospace Engineering & Tecnology
Journal title
ISSN journal
00218669
Volume
31
Issue
5
Year of publication
1994
Pages
1050 - 1056
Database
ISI
SICI code
0021-8669(1994)31:5<1050:AOAOJA>2.0.ZU;2-Z
Abstract
An attempt is made to enhance the beneficial effects of the trapped vo rtex by increasing its lingering period on the upper surface of a Jouk owski airfoil in oscillating motions. Studies are made on the stabilit y of a trapped free vortex when perturbed away from its equilibrium po sition with a finite displacement, and on the lingering period of the trapped free vortex in the upper vicinity of the airfoil. The computat ional results show that a proper combination of oscillation and suctio n might be an efficient method for trapping a free vortex to generate high lift on an airfoil. It is found that the trailing-edge suction po sition is more effective in capturing a free vortex for a longer linge ring time and the lift increment directly dependent on the strength of the trapped vortex. This result may provide an explanation of the hig h lift generated by a dragonfly whose back wings are found to flap in a flow containing vortices shed from the front wings.