内孤立波环境下圆柱和方柱受力特征——Ⅰ.物理实验

Force behaviors of circular and square cylinder in internal solitary waves environment:Ⅰ:experimental investigation

随着近岸海洋的开发,海洋石油钻井平台底部的柱状支撑以及海洋中石油管线等水下结构物的安全问题受到的关注日益增多。而内孤立波对水下结构物的安全有着不可忽视的影响,这就决定了内孤立波对柱体受力的研究在工程实践中具有重要意义。国内外就内孤立波对柱体作用力的物理试验研究较少,而在分层流环境下圆柱和方柱受力规律的对比研究更鲜有报道。在大型重力式分层流试验水槽中,借助一套新型且专用于分层流环境下的内孤立波造波及水动力测力系统,进行了内孤立波环境下柱体受力规律的试验研究。对比分析了不同内孤立波波幅对圆柱和方柱受力的作用规律。研究表明,在分层流环境下,随着内孤立波波幅的增大,圆柱和方柱所受的水平作用力均增大;相同波幅情况下,方柱相较于圆柱会受到更大的水平力。研究成果可为分层流环境中柱体设计及安全评价提供科学依据。

With the development of offshore engineering, increasing attention has been devoted to the safety of the underwater structures, such as the bottom-supported piles of offshore oil drilling platforms and offshore petroleum pipe- lines. For internal solitary waves （ISWs） exert a neglected influence on the safety of underwater structures, studying ISW forces acting on cylinders is highly significant. 0nly a few studies have been conducted on ISW forces acting on cylinders, and studies that compare the forces acting on circular and square cylinders in a stratified fluid environment are scarce. Experimental investigations of the forces exerted by ISWs on circular and square cylinders are performed in a stratified fluid tank using a new device to generate ISWs and a measurement system for ISWs loads. Comparisons of ISW force behaviors in the two cylinders are studied at various ISW amplitudes. Results show that the forces exerted on the circular and square cylinders increase with increasing wave amplitudes. At the same wave amplitude, the ISW forces on the square cylinder are larger than those on the circular cylinder. This study provides guidance for cylinder design and safety evaluation in a stratified fluid environment.