龙卷风风场下水面船舶倾覆的力学机理研究

发布时间：2018-05-14 18:03

本文选题：龙卷风 + 风荷载　；参考：《西安交通大学学报》2016年05期

【摘要】：为研究龙卷风风场对船舶稳定性的影响,利用龙卷风风场模型分析了船舶风荷载特性及其随方位的变化规律。龙卷风风场模型在柱坐标系下形成并假定流场定常,龙卷风的漏斗外形轴对称,且从外围到中心的气压降主要由切向风速产生的离心力来平衡;以"东方之星"船舶简化模型为例,计算了船舶的最小倾覆力矩,并从船舶航向以及船舶位于龙卷风风场的不同径向位置分析了船舶倾覆的力学条件。研究结果表明:船舶航向垂直于龙卷风的径向时,船两侧负压差大于最小倾覆力矩,从而导致船舶倾覆;船舶航向平行于龙卷风的径向时,船舶受高速风的冲击而发生倾覆,倾覆方向与龙卷风的切向一致;船舶航向与龙卷风风场径向成任意夹角时,倾覆取决于船舶相对于龙卷风中心的位置、龙卷风切向风速以及船舶航速。该结果可为船舶设计及龙卷风预警研究提供参考。
[Abstract]:In order to study the influence of tornado wind field on ship stability, the wind load characteristics of ship and its variation law with azimuth are analyzed by using tornado wind field model. The tornado wind field model is formed in the cylindrical coordinate system and assumed that the flow field is steady. The funnel shape of the tornado is axisymmetric and the pressure drop from the periphery to the center is mainly balanced by the centrifugal force generated by the tangential wind speed. Taking the simplified model of "East Star" ship as an example, the minimum overturning moment of the ship is calculated, and the mechanical conditions of the ship capsizing are analyzed from the ship's course and the different radial positions of the ship in the tornado wind field. The results show that when the ship's course is perpendicular to the radial direction of the tornado, the negative pressure difference on both sides of the ship is greater than the minimum overturning moment, which results in the ship overturning, and when the ship's course is parallel to the tornado's radial direction, the ship is capsized by the impact of high speed wind. The capsizing direction is consistent with the tangential direction of tornado, and when the direction of ship and tornado wind field is at any angle, the capsizing depends on the position of the ship relative to the center of the tornado, the tangential wind speed of the tornado and the speed of the ship. The results can provide reference for ship design and tornado warning research.
【作者单位】：西安交通大学人居环境与建筑工程学院;武汉理工大学能源与动力工程学院;
【基金】：国家自然科学基金资助项目(40675011,10872159)
【分类号】：U661

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