Impacts of the bottom vortex on the surrounding flow characteristics of a semi-submerged rectangular cylinder under four aspect ratios

IF 1.3 4区工程技术 Q3 ENGINEERING, MECHANICAL

Journal of Offshore Mechanics and Arctic Engineering-Transactions of the Asme Pub Date : 2023-10-20 DOI:10.1115/1.4063853

Jiaqi Zhou, Junsheng Ren, Dongyue Li, Can Tu, Weiwei Bai

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引用次数: 0

Abstract

Abstract Vortex has attracted attention because it is the main factor affecting the flow characteristics around offshore structures. This paper researches the flow field variations around a semi-submerged rectangular cylinder (SRC) under four aspect ratios, thereby revealing the bottom vortex effects on the flow field at Reynolds number = 36300. According to the particle image velocimetry (PIV) data, the RNG k-ε model is selected as an applicable turbulence model for studying SRC flow characteristics. From the results, the bottom vortex generation and streamwise velocity are inseparable. As the draft increases, the increased range of the bottom vortex would directly interfere with the flow characteristic around the SRC. Since the wake vortex forms a reattachment state when the SRC pierces the free surface, its flow field could be disturbed by the bottom vortex. Furthermore, the bottom vortex also affects the extreme point position of the boundary layer characteristic at the SRC bottom.

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四长弦比下底部涡对半淹没矩形圆柱周围流动特性的影响

摘要涡旋是影响海上构筑物周围流动特性的主要因素，一直受到人们的关注。本文研究了四种展弦比下半淹没矩形圆柱(SRC)的流场变化，揭示了雷诺数= 36300时底部涡对流场的影响。根据颗粒图像测速(PIV)数据，选择RNG k-ε模型作为研究SRC流动特性的适用湍流模型。从结果来看，底部涡的产生与流向速度是密不可分的。随着气流的增大，底部涡的增大幅度会直接影响到SRC周围的流动特性。由于尾迹涡在SRC穿透自由表面时形成再附着状态，其流场会受到底部涡的干扰。此外，底涡还会影响SRC底部边界层特征极值点的位置。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Offshore Mechanics and Arctic Engineering-Transactions of the Asme 工程技术-工程：大洋

CiteScore

4.20

自引率

6.20%

发文量

审稿时长

6-12 weeks

期刊介绍： The Journal of Offshore Mechanics and Arctic Engineering is an international resource for original peer-reviewed research that advances the state of knowledge on all aspects of analysis, design, and technology development in ocean, offshore, arctic, and related fields. Its main goals are to provide a forum for timely and in-depth exchanges of scientific and technical information among researchers and engineers. It emphasizes fundamental research and development studies as well as review articles that offer either retrospective perspectives on well-established topics or exposures to innovative or novel developments. Case histories are not encouraged. The journal also documents significant developments in related fields and major accomplishments of renowned scientists by programming themed issues to record such events. Scope: Offshore Mechanics, Drilling Technology, Fixed and Floating Production Systems; Ocean Engineering, Hydrodynamics, and Ship Motions; Ocean Climate Statistics, Storms, Extremes, and Hurricanes; Structural Mechanics; Safety, Reliability, Risk Assessment, and Uncertainty Quantification; Riser Mechanics, Cable and Mooring Dynamics, Pipeline and Subsea Technology; Materials Engineering, Fatigue, Fracture, Welding Technology, Non-destructive Testing, Inspection Technologies, Corrosion Protection and Control; Fluid-structure Interaction, Computational Fluid Dynamics, Flow and Vortex-Induced Vibrations; Marine and Offshore Geotechnics, Soil Mechanics, Soil-pipeline Interaction; Ocean Renewable Energy; Ocean Space Utilization and Aquaculture Engineering; Petroleum Technology; Polar and Arctic Science and Technology, Ice Mechanics, Arctic Drilling and Exploration, Arctic Structures, Ice-structure and Ship Interaction, Permafrost Engineering, Arctic and Thermal Design.