Design improvements of the smart active trailing-edge flap (ATF) for rotating test

Abstract

In this dissertation, small-scaled blade prototypes with the flap-driving mechanism, called SNUF (Seoul National University Flap), were manufactured, and tested in order to realize vibratory load reduction in the rotor system. It was achieved by an active trailing-edge flap which is based on piezoelectric actuator. However, it turned out that the target value (±4°) of the flap deflection angle was not accomplished in the previous designs. Therefore, the flap driving mechanism needs to be amended. Thus, a new piezoelectric actuator was selected to achieve the target deflection by considering the nonlinear relationship between flap deflection angle and the moment arm length. Re-selection of the actuator required increase of the blade inner space and its size. Therefore, it was required to validate the cross-sectional design of the improved blade configuration. So as to verify the structural integrity, cross-sectional analysis was conducted by using UM/VABS. Revised flap driving mechanism and its test-bed shows quite satisfactory result during the static bench test even though there still remain several issues which should be solved. After completion of the non-rotating static test of the new flap-driving mechanism, a prototype blade will be manufactured and tested in the whirl tower