Transient Flow Analysis and Static Bench Measurements for an Active Trailing-Edge Flap

The paper discusses the analyses implemented for the design improvement of the SNUF (Seoul National University Flap), a small-scaled flap-driving mechanism aimed at reducing vibratory loads in a helicopter rotor. Predictions of the hinge moment, both in steady and transient flow, were obtained through CFD (Computational Fluid Dynamics) calculations. When compared with results originating from theoretical formulation, it showed good correlation. Furthermore, the displacement occurring in the piezo-ceramic stack according to different frequencies was measured thanks to a further capable highvoltage amplifier able to span through the actuating frequency range, namely 0-65 Hz. Future proceedings aimed at verifying the effect of centrifugal loads in the SNUF, such as pulling test and contact analysis, are also illustrated.