Data analysis of simulated hydrofoil oscillations in a steady flow field using intelligent higher-order statistical processing

Data analysis of an oscillating flapping wing is conducted for developing a transfer function model especially for heave force data series from the CFD environment for different geometries of flapping wings. The wing experiences a combination of vertical and angular oscillatory motion, while travelling at constant forward speed. The vertical motion is induced by the random motion of the ship in waves, essentially due to ship heave and pitch, while the wing pitching motion is selected as a proper function of wing vertical motion and it is imposed by an external mechanism. The data series obtained by simulation of the unsteady lifting flow around the system was applied to develop a closed-form lumped phenomenological model for fin motion control synthesis. Using this model a statespace controller for thrust augmentation flappers will be developed as part of a future work. Therefore, the post processing of the data series of thrust-producing flapping foils can in effect be a useful application for control surface feedback law design.