Effect of active gurney flaps on overall helicopter flight envelope

Pastrikakis, V.A., Steijl, R. and Barakos, G.N. (2016) Effect of active gurney flaps on overall helicopter flight envelope. Aeronautical Journal, 120(1230), pp. 1230-1261. (doi: 10.1017/aer.2016.57)

Abstract

This paper presents a study of the W3-Sokol main rotor equipped with Gurney flaps. The effect of the a active Gurney is tested at low and high forward flight speeds to draw conclusions about the potential enhancement of the rotorcraft performance for the whole flight envelope. The effect of the flap on the trimming and handling of a full helicopter is also investigated. Fluid and structure dynamics were coupled in all cases, and the rotor was trimmed at different thrust coefficients. The Gurney proved to be efficient at medium to high advance ratios, where the power requirements of the rotor were decreased by up to 3.3%. However, the 1/rev actuation of the flap might be an issue for the trimming and handling of the helicopter. The current study builds on the idea that any active mechanism operating on a rotor could alter the dynamics and the handling of the helicopter. A closed loop actuation of the Gurney flap was put forward based on a pressure divergence criterion, and it led to further enhancement of the aerodynamic performance. Next, a generic light utility helicopter was built using 2D aerodynamics of the main aerofoil section of the W3 Sokol blade along with a robust controller, and the response of the rotorcraft to control inputs was tested. This analysis proved that the 1/Rev actuation of the Gurney did not alter the handling qualities of the helicopter, and as a result it can be implemented as a flow control mechanism for aerodynamic enhancement and retreating blade stall alleviation.

• Item Type: Articles
• Additional Information: The financial support via the IMESCON Marie Curie ITN project (grant agreement number: 264672), the release of the W3 Sokol main rotor blade geometry by PZL Swidnik, the use of the computing centre TASK of Gdansk, Poland, and the contribution of Axsym Engineering in the post-processing of the flight test data are gratefully acknowledged. Some of the CFD results were obtained using the Jupiter cluster of CFD Lab of University of Glasgow and the EPSRC funded ARCHIE-WeST High Performance Computer (www.archie-west.ac.uk). EPSRC grant number: EP/K000586/1.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Barakos, Professor George and Steijl, Dr Rene
• Authors: Pastrikakis, V.A., Steijl, R., and Barakos, G.N.
• College/School: College of Science and Engineering > School of Engineering > Autonomous Systems and Connectivity
• Journal Name: Aeronautical Journal
• Publisher: Royal Aeronautical Society
• ISSN: 0001-9240
• ISSN (Online): 2059-6464
• Published Online: 07 June 2016
• Copyright Holders: Copyright © 2016 Royal Aeronautical Society
• First Published: First published in Aeronautical Journal 2016
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher.