A CFD-CSD Coupled-Analysis of HART-II Rotor Vibration Reduction Using Gurney Flaps

A dynamically deployed Gurney flap was examined as an active control device for rotor vibration reduction. A CFD-CSD coupled analysis was carried out to include the aeroelastic effects and to maintain trimmed state. The four-bladed HART-II model was used as a representative rotor. 2-D analyses were performed to investigate the air load response to the Gurney flap deployment, specifically the time lag effects, and determine initial flap deployment schedules. The four-per-revolution deployments of the Gurney flap on lower and upper surfaces were simulated and the resulting vertical vibratory loads were compared with the baseline rotor. The simulations indicate that a 83% reduction of the four-per-rev vibratory load may be achieved while maintaining the trim state without significant performance penalty. It was also shown that the four-per-rev vibratory load may also be virtually eliminated using an optimized deployment of the Gurney flap. Simultaneous reduction of four-per-rev and eight-per-rev components of vibratory loads was achieved using individual control of segmented Gurney flaps distributed along the radial direction.