随机波列中极端波浪波形和波高分布的数值试验研究  

Numerical study on the shape of extreme waves and wave height distribution in random wave trains

作　　者：夏维达 马玉祥[1] 董国海[1] XIA Weida;MA Yuxiang;DONG Guohai(Institute of Ocean Engineering,State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]大连理工大学海岸与近海工程国家重点实验室,辽宁大连116024

出　　处：《哈尔滨工程大学学报》2023年第9期1534-1541,共8页Journal of Harbin Engineering University

基　　金：国家自然科学基金项目(51720105010).

摘　　要：极端波浪对近岸和海洋结构物存在着极大威胁,结构物的设计必然需要考虑极端波浪的影响,因此对波浪波高分布和极端波浪波形的研究对工程设计有重要的意义。为了能够准确地预测各种海况下波浪的分布和结构物的响应,本文在二维数值非线性波浪水槽中模拟了有限水深中随机波浪的传播过程产生的极端波浪,分析了谱参数对极端波浪波形的影响,并对比随机波浪的波高和波峰分布与理论分布。Tromans提出的新波模型从概率角度给出了极端波浪最有可能波形。结果表明:三阶新波模型能够较好地描述极端波浪的波形;但是在波陡较大时,实际波浪更为陡峭,并且具有明显的高波峰浅波谷的特点,新波模型的误差增大。MER分布和三阶Tayfun分布在极端波高范围内能够较好地吻合实际波高分布,而二阶Tayfun分布和Forristall分布仅适用于波陡较小情况的极端波出现概率预测。Extreme waves pose a great threat to coastal and offshore structures,and their effect must be taken into account in the design of structures.Therefore,the study of wave height distribution and extreme wave shape is of great importance to engineering design.In order to predict the wave height distribution and the response of offshore structures accurately,numerical simulations of wave propagation with various wave parameters were conducted in a 2-D flume.Influence of wave steepness and bandwidth on averaged extreme wave profiles were analyzed.Wave height and wave crest distribution of simulated surface elevation were compared with theoretical estimations.The new wave theory was proposed by Tromans to calculate the most probable ocean surface elevation through probabilistic analysis.The results show that third-order new wave model has the ability to replicate averaged extreme waves under intermediate water depth.However,simulated average extreme waves presents a steeper wave profile,a sharper crest and a more rounded trough compared to new wave model under high steepness conditions.MER and third-order Tayfun distribution matches the observed distribution of wave heights.Second-order Tayfun and Forristall distribution are only valid for conditions with low steepness.

关 键 词：极端波浪 平均波形 新波模型 数值模拟 波高分布 高阶谱模型 随机波浪 非线性波浪 

分 类 号：TV139.2[水利工程—水力学及河流动力学]