Identification of Flapper Fin Oscillations for Active Flow Control Applications in Improved Watercraft Propulsion

摘要

In this study, the data analysis of an oscillating flapping wing isconducted for the development of a describing function modelespecially for heave force data series obtained using a BoundaryElement Method (BEM) for different geometrical kinds of flappingwings. The wing experiences a combination of vertical and angularoscillatory motion, while travelling at constant forward speed. Thevertical motion is induced by the random motion of the ship in waves,essentially due to ship heave and pitch, while the wing pitching motionis selected as a proper function of wing vertical motion and it isimposed by an external mechanism. The data series obtained bysimulation of the unsteady lifting flow around the system was appliedto develop a closed-form lumped phenomenological model for finmotion control synthesis. Using this model a state-space controller forthrust augmentation flappers will be later developed. Our studyconcerning post-processing data series of thrust-producing flappingfoils can in effect be a useful application for feedback control lawdesign.