Investigation of hydroelasticity in water entry of flexible wedges with flow detachment

Abstract

Prediction of structural response during water entry is of great significance for the design of naval architecture and aircraft. In order to study fluid-structural interaction (FSI) of flexible wedge during water entry, coupling algorithms based on boundary element method (BEM)/Wagner theory and modal superposition method (MSM) are utilized. The first solution is a numerical method by coupling BEM and MSM based on domain decomposition technique. The second solution is a semi-analytical method by coupling Wagner theory and MSM. Non-linear pressure composition in the Bernoulli equation is used to improve the accuracy for wedge with moderate deadrise angles. The implicitly Newmark-β scheme is employed for time marching of structural dynamic equation. Effects of hydroelasticity on fluid pressure and structural response are studied by the comparison between coupling and decoupling solutions. The results show that the structural response is significantly affected by the presence of fluid added mass and damping. Structural response is lagged due to the fluid added mass and damping. Besides, the latter one causes the decrease of amplitudes of slamming load and structural response. This paper highlights the effect of hydroelasticity on slamming load and structural response during water entry of flexible structure.