近岸沙坝海滩裂流数值模拟与动力学分析  

Nearshore Rip Currents Simulation and Dynamical Analysis with Sand Bar Beach

作　　者：衣骊安 张希彬 YI Li'an;ZHANG Xibin(Northwest University,Xi'an 710127,China;Tianjin University of Science&Technology,Tianjin 300457,China)

机构地区：[1]西北大学,陕西西安710127 [2]天津科技大学,天津300457

出　　处：《海洋技术学报》2022年第6期25-33,共9页Journal of Ocean Technology

基　　金：天津市高等学校基本科研业务经费资助项目(2018KJ12);天津市应用基础与前沿技术研究计划项目(19JCYBJC22000)。

摘　　要：裂流是海滨旅游区的重要安全隐患,世界范围内80%以上的海滩救援事件都与裂流有关。本文基于FUNWAVE非线性波浪分辨模型,对近岸常见沙坝海滩裂流灾害进行数值模拟,给出裂流过程中的平均海平面水位、均方根波高、涡流场和裂流流场的分布特征。设计敏感实验,研究了入射波高、波角和潮汐水位大小对裂流灾害的影响。入射波高增加,裂流风险增大,低潮汐水位,对应的裂流强度在增加。入射波角的增加,能够使离岸流速分量减少,使裂流风险减少。通过计算不同时间间隔的裂流平均流速,研究不同时间平均对裂流流速的影响,说明利用波浪平均模型,得到较大时间间隔的裂流平均流速,通常能够低估裂流流速,计算的裂流风险不够准确,而利用FUNWAVE波浪分辨模型,能够精确地模拟计算裂流瞬时流速和流速阈值,适合对裂流灾害进行模拟和评价。Rip current is an important security risk in coastal tourism areas.More than 80%of the world’s Beach rescue events are related to split flow.In this paper,based on the FUNVAVE resolution model,the numerical simulation of the sandbar beach crack flow disaster is carried out.In this paper,the characteristics of offshore flow formed in sandbar terrain are studied.It is showed that the rippled flow can be produced by sand bar channel terrain,and the dynamic characteristics of the rippled flow are described.According to the common sandbar groove beach topography,the FUNVAVE model is used to simulate the crack flow disaster.The distribution characteristics of mean sea level,mean square root wave height,eddy current field and fissure flow field in the process of fissure flow disaster are given.The effects of incident wave height,wave angle and tide size on the crack flow disaster are studied by setting up sensitive experiments.By calculating the average velocity of split flow in different time intervals,the change of mean sea level,eddy current field and maximum average velocity is studied.It is shown that the simulation results can generally underestimate the split flow velocity and flow direction by using wave average model,so as to reduce the risk of split flow.However,by using FUNVAVE resolution model,the instantaneous velocity and flow threshold of split flow can be accurately simulated and calculated,which is suitable for the disaster of split flow and the evaluation.

关 键 词：裂流 沙坝海滩 裂流槽 数值模拟 FUNWAVE 

分 类 号：P731.2[天文地球—海洋科学]