A new engineering theory describing oblique free surface impact by flexible plates

Abstract

Consideration of slamming loads within the structural design of planning hulls is of critical importance in ensuring adequate structural performance. However, a general engineering theory for slamming has yet to be uncovered due to the intricacy in the interplay between complex fluid flows and nonlinear structural deformations, and so design relies on specialized theories. We propose one such theory for a design case that has, until now, eluded a proper description. In pursuit of this theory, we employ an implicit, partitioned fluid-structural interaction (FSI) simulation approach, to study the underlying physical mechanisms accompanying the oblique impact of a flexible plate during water entry. In the present work, we first present validation results from flexible plate water entry experiments (our FSI results display satisfactory alignment compared with experimental data). Subsequently, we carry out a series of numerical analyses to characterize the impact force and plate out-of-plane deformations. Finally, we use our FSI solver to study the mechanistic evolution of fluid flows and elastic plate deformations that occur during slamming. Based on these observations, we propose a novel engineering theory for flexible plates obliquely impacting the water free surface. Our proposed theory presents excellent predicative capability compared with FSI solutions.