Control of rotorcraft retreating blade stall using air-jet vortex generators

Singh, C., Peake, D. J., Kokkalis, A., Khodagolian, V., Coton, F.N. and Galbraith, R. A. M. (2006) Control of rotorcraft retreating blade stall using air-jet vortex generators. Journal of Aircraft, 43(4), pp. 1169-1176.

Abstract

A series of low-speed wind tunnel tests were carried out on an oscillating airfoil fitted with two rows of air-jet vortex generators (AJVGs). The airfoil used had an RAE 9645 section and the two spanwise arrays of AJVGs were located at x/c=0.12 and 0.62. The devices and their distribution were chosen to assess their ability to modify/control dynamic stall; the goal being to enhance the aerodynamic performance of helicopter rotors on the retreating blade side of the disc. The model was pitched about the quarter chord with a reduced frequency (k) of 0.1 in a sinusoidal motion defined by a=15o+10sin_ t. The measured data indicate that, for continuous blowing from the front row of AJVGs with a momentum blowing coefficient (C μ) greater than 0.008, modifications to the stalling process are encouraging. In particular, the pitching moment behavior exhibits delayed stall and there is a marked reduction in the normal force hysteresis.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Coton, Professor Frank
• Authors: Singh, C., Peake, D. J., Kokkalis, A., Khodagolian, V., Coton, F.N., and Galbraith, R. A. M.
• Subjects: T Technology > TL Motor vehicles. Aeronautics. Astronautics
• College/School: College of Science and Engineering > School of Engineering > Autonomous Systems and Connectivity
• Journal Name: Journal of Aircraft
• Publisher: American Institute of Aeronautics and Astronautics
• ISSN: 1533-3868
• Copyright Holders: Copyright © F.N. Coton
• First Published: First published in Journal of Aircraft 43(4):1169-1176
• Publisher Policy: Reproduced with the permission of the author