Computational Investigation of Gurney Flap Effects on Rotors in Forward Flight

Abstract

A hybrid Navier-Stokes/free-wake solver has been employed to investigate the performance of a rotor equipped with a Gurney flap in steady level flight and in descent. A scaled model of the BO-105 rotor was studied. The calculations were coupled to a comprehensive analysis to properly account for the effects of the elastic deformations on the aerodynamic loads and to account for trim. Fixed and dynamically deployed Gurney flaps were considered. In forward flight, it was found that a properly chosen azimuthal deployment schedule of the Gurney flaps may reduce the peak-to-peak variations in hub loads, potentially reducing vibrations. In descent flight, it was found that the deployment of a fixed Gurney flap decreased the descent rate needed to maintain autorotation.

Computational aeroelastic analysis of a hovering W3 Sokol blade with gurney flap

“…Comparing the above studies by Min et al (2009, and Bae and Gandhi (2012), to the ones conducted by Milgram et al (1998), and Viswamurthy and Ganguli (2004) it seems that a gurney flap can have a similar effect on the vibratory loads of the rotor hub like a conventional trailing edge flap. A typical flap is suggested by Viswamurthy and Ganguli (2004) on a soft hingeless rotor leading to a 72% reduction of the vibratory loads.…”

“…Min et al (2009) studied the effects of gurney flaps on the blade root loads and hub vibratory loads. In their study, a gurney flap was deployed over the entire span of the BO-105 rotor in forward flight with three different deployment schedules.…”

Aerodynamic Evaluation of Miniature Trailing-Edge Effectors for Active Rotor Control

“…Recently, they have also shown potential for solving several problems associated with dynamic stall of rotorcraft blades (Ref. [8][9][10][11][12][13]). An array of MiTEs deployed successfully on rotorcraft blades could potentially be used for performance enhancement, vibration and noise reduction, increased maneuverability, and automated blade tracking.…”

Method for Calculating Rotors with Active Gurney Flaps

“…If a Gurney flap is to be added to a rotor blade, a passive device will lead to a fully deployed Gurney through the whole azimuth as in the study of Min et al [15], while an active Gurney could be deployed on demand. In that case, it could be fully deployed in hover flight to increase the lift capability of the rotor, while in forward flight it could be retracted at the advancing side and deployed actively at the retreating side of the rotor.…”

“…As an example, Min et al [15] studied the effects of Gurney flaps on the blade root loads and hub vibratory loads. In their study, a Gurney flap was deployed over the entire span of the blade.…”