Fluid-structure interaction problem of hydrodynamic motion of an independent escape capsule under variable constraint conditions. (1st September 2019)

• Record Type: Journal Article
• Authors: Zhang, Lei; Kong, Bin; Lin, Shiyao; Wang, Chizhong; Xie, De; Sun, Jianglong
• Is Part Of: Ocean engineering. Volume 187(2019)
• Publication Date: 2019-09-01
• Subjects: Fluid-structure interaction -- Hydrodynamic motion -- Added-mass effect -- Various constraint conditions -- Independent escape capsule; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2019.106198
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: Hydrodynamic behavior of an independent escape capsule from a disabled submarine is a complex six-degrees-of-freedom motion, in which added-mass effect is strong and variable constraint conditions happen. In this paper, loosely (or weakly) coupled scheme is adopted to solve this fluid-structure interaction problem. Flow field is simulated by Fluent (version 13.0.1) and motion equations are solved by the fourth-order Runge-Kutta method separately. Unstructured dynamic mesh technology is used to trace the trajectory of capsule. Hydrodynamic force is decomposed into resistance and added mass force, and new motion equations are derived in order to handle the huge added mass. The surfaces of capsule and its chamber come into contact randomly. The variable constraint conditions are analyzed and their corresponding kinematical equations are introduced. This loosely coupled scheme is applied to study the hydrodynamic behavior of a two-dimensional capsule from a narrow space into an open domain under different ocean currents. Hydrodynamic force, motion characteristics and trajectory are obtained. The simulation indicates that the velocity and direction of flow strongly affect the motion of capsule, and the contact force leads to the jamming problem of capsule during its ejection process. Highlights: A loosely coupled scheme is proposed for fluid-structure interaction problem under variable constraint conditions. Fluid-structure interaction problem with strong added-mass effect is studied. Added mass of rigid body in finite fluid domain is calculated. Motion characteristics and trajectory of an ejected capsule inside a chamber are analyzed. The effect of ocean currents on ejection performance of capsule is discussed.