摘要
为研究下击暴流作用于海洋上层水域的风场特性与风浪分布,基于CFD(computational fluid dynamics)技术,建立了二维几何模型,使用雷诺应力模型、多相流模型对二维下击暴流作用于海洋上层水域的过程进行数值模拟,开展了其速度变化时程、波高变化时程、特征时刻径向风速剖面、时均风速剖面与液相流速剖面的变化特性的分析.模拟结果表明:相对于平面陆地,下击暴流作用于海洋上层水域的前期径向气流方向有所抬升,风场稳定后径向气流中部仍表现为小幅抬升,至冲击中心水平方向远处逐渐平稳;冲击中心附近的海洋上层表面随下击暴流持续作用表面产生下凹,随时间增加下凹加剧,产生的冲击波向两侧传递,随时间发展在径向气流作用下产生长短不一的波;早期径向风速值将超过初始下沉气流风速值,最大达到下沉气流速度值的1.2倍,易联合风浪作用使海上舰船发生倾覆,海上舰船应利用其特征防范与抵御下击暴流;径向时均风速最大值所在高度较下击暴流作用于陆地时要高.
For the purpose of studying wind-field characteristics and wind-wave distributions of downburst acting on the upper ocean waters,a two-dimensional geometric model is established,and Reynolds stress model and multiphase flow model are used for numerical simulations.The velocity time-history,wave height time history,radial wind velocity profile at different instants,time-averaged wind velocity profile and liquid velocity profile are analyzed.These simulation results show that,compared with the land surface topography,the radial flow direction of the downburst acting on the upper ocean waters in the early stage has been uplifted.After the wind field is stabilized,the central part of the radial flow remains slightly uplifted and gradually stabilizes far away from the horizontal direction of the impact center.The surface of the upper ocean near the impact center appears concave under the continuous action of the downburst,which intensifies with the increase of time.The resulting shock wave is transmitted to both sides,and waves of different lengths are generated under the action of radial airflow.In early times,the radial wind speed value will exceed the initial downdraft wind speed value and reaches a maximum value of 1.2 times of the downdraft speed value,combining the action of wind and waves to capsize ships at sea.These characteristics of downburst investigated in this study can be adopted for ships at sea to prevent and resist the downdraft.Finally,we have shown that the height of the maximum radial average wind speed is higher at sea than that at the land under the action of the downburst.
作者
尤韩炜
陈昌萍
YOU Hanwei;CHEN Changping(School of Architecture and Civil Engineering,Xiamen University,Xiamen 361005,China;Fujian Provincial Key Laboratory of Wind Disaster and Wind Engineering,Xiamen University of Technology,Xiamen 361024,China;Xiamen Ocean Vocational College,Xiamen 361003,China)
出处
《厦门大学学报（自然科学版）》
CAS
CSCD
北大核心
2022年第4期572-578,共7页
Journal of Xiamen University：Natural Science
基金
国家自然科学基金(52178510)。
关键词
下击暴流
气液两相流
风剖面
数值模拟
downburst
gas-liquid two-phase flow
wind profile
numerical simulation
