Longitudinal Stability Augmentation of Seaplanes in Planing

Abstract

The towing tank experiments conducted at the Yokohama National University from November 30 to December 9 in 2005, suggested a new way of suppressing a dangerous coupled motion between heave and pitch called porpoising. This research develops on the observations made in the experiments and conducts numerical simulations to further investigate the parametric design space. Two Linear-Time-Invariant models were developed: rigid-body planing craft (conventional float planes or flying boats) and flexibly supported planing craft. The latter can simulate the new method found in the experiments for suppressing porpoising. In this study, the stability of the oscillatory motions was analyzed to see the effect of design variables to the inception of porpoising. The parametric study of flexibly supported float planes in the context of porpoising is a new contribution in the conceptual design of seaplanes.