SWAN模型中不同风拖曳力系数对风浪模拟的影响  

Impact of wind drag coefficients on wave simulation using SWAN model

作　　者：丁磊 于博 

机构地区：[1]天津科技大学海洋与环境学院,天津300457 [2]天津市海洋环境与修复技术工程中心,天津300457

出　　处：《海洋学报》2017年第11期14-23,共10页

基　　金：国家自然科学基金项目(41276016);国家科技支撑计划资助项目(2010BAC68B04);天津科技大学科学研究基金资助项目(20130113)

摘　　要：本文以荷兰哈灵水道海域为实验区域,通过敏感性实验,研究了在14m/s、31.5m/s和50m/s(分别代表一般大风、强热带风暴和强台风的极端条件)定常风速下SWAN模型中不同风拖曳力系数对风浪模拟的影响程度。结果表明,对于近岸浅水区域(水深小于20m),风拖曳力系数计算方案的选择对有效波高影响较小,而且当风速增加到一定程度后,波浪破碎成为影响波高值的主要因素;对于深水区域(水深大于30m),一般大风条件下风拖曳力系数计算方案的选择对有效波高影响仍然较小,随着风速的继续增大,风拖曳力系数计算方案的选择对有效波高的影响逐渐显著。对于平均周期,风拖曳力系数计算方案的选择和风速的改变对其影响均较小,而由水深变浅导致的波浪破碎对其影响较为显著。根据敏感性实验结果,本文对SWAN模型中风拖曳力系数计算方案的选择做出如下建议:计算近岸浅水区域风浪场或深水区域一般大风条件风浪场时,其风拖曳力系数可以直接采用模型默认选项;而对于深水区域更大风速条件,可首先采用模型默认选项试算,然后结合当地海域实测波浪资料进行修正。Impact of wind drag coefficients in SWAN model on wave simulation was studied in the paper.Sensitivity experiments were conducted under wind speed 14 m/s,31.5 m/s and 50 m/s（representing the conditions of strong wind,strong tropical storm and strong typhoon,respectively）.Haringvliet in Holland was chosen as experimental area.Results show that in shallow water（shallower than 20 m）,the wind drag coefficient has little effect on significant wave height.When the wind speed reaches a certain speed,wave breaking becomes a major factor affecting the significant wave height.In deep water（deeper than 30 m）,the effect of wind drag coefficients on significant wave height is still small in condition of strong wind.As the wind speed increases further,the influence of wind drag coefficients on significant wave height becomes obvious gradually.The wind drag coefficient and wind speed have little influence on mean wave period whereas the wave breaking affects it significantly.According to the results of sensitivity experiments,choice of wind drag coefficients in SWAN model is suggested as follows.When the wind waves in shallow water are simulated,the default wind drag coefficient in SWAN can be directly used.As for deep water case,the default wind drag coefficient can be applied in condition of strong wind.When the wind speed is higher,the default wind drag coefficient can be tested firstly,and then it can be modified in terms of the field data if needed.

关 键 词：风拖曳力系数 SWAN模型 风浪模拟 有效波高 平均周期 

分 类 号：P731.22[天文地球—海洋科学]