Hydroelastic Response of Surface-Effect Ship Bow Seals:Large-Scale Experiments and Post-Buckling Analysis.

Fluid Structure Interaction;Bow Seal;Fabric Folding;Surface-effect Ship;Air-cushion Vehicle;Soft-matter;Aerospace Engineering;Mechanical Engineering;Naval Architecture and Marine Engineering;Engineering;Naval Architecture & Marine Engineering

Wiggins, Andrew D.Young, Yin Lu ;

University of Michigan

关键词: Fluid Structure Interaction;    Bow Seal;    Fabric Folding;    Surface-effect Ship;    Air-cushion Vehicle;    Soft-matter;    Aerospace Engineering;    Mechanical Engineering;    Naval Architecture and Marine Engineering;    Engineering;    Naval Architecture & Marine Engineering;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/107098/awiggs_1.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Bow seals are critical components on advanced marine vehicles that rely on aerostatic support to reduce drag. They consist of a series of open-ended fabric cylinders (;;fingers;;) that contact the free surface and, when inflated, form a compliant pressure barrier. Bow seals are unique in that, unlike a majority of structures in civil and mechanical engineering, bow seals operate in a buckled state.The response characteristics of these structures are of practical interest due to unacceptable wear rates on seal components and difficulties in predicting seal performance. Despite this, the hydroelastic response of the seal system, particularly basic information on seal vibration modes and the mechanisms responsible for seal wear, remains largely unknown. Similarly, estimates of the hydrodynamic loads on the seal system are inaccurate and based on heuristic scaling of data from small-scale experiments, where similitude is challenging to maintain. Thus, a large-scale test system is necessary to obtain accurate estimates of bow seal response.The work is comprised of three parts. Part one presents detailed observations of bow seal response acquired using a large-scale test platform developed as part of the present study. These high-resolution observations, the first of their kind, show bow seal response to be characterized by complex post-buckling behavior. Part two proposes an analytical framework for interpreting the wide range of behavior observed at large scale. Using this framework, key parameters driving seal conformation and stability are identified. It is found that, due to their buckled state, bow seals are highly susceptible to a mode switching instability, which may be a potential mechanism responsible for the damaging vibrations. In part three, a benchtop experiment is used to demonstrate that the scalings identified in this study hold across a wide range of bending rigidities. This work has implications for improving drag and wear characteristics in future bow seal designs. In addition, the scaling parameters identified in this study may govern buckling in other physical systems, such as ice sheets and biological membranes.