单向不规则波群的实验室模拟和分析

Experimental simulation and analysis of irregular sea wave groups

文章基于改进的波包谱经验公式,建议了单向不规则波群的数值模拟方法,模拟实例表明,只要给定波要素及描述波浪群性的高度特征参数和长度特征参数,即可通过此波包谱方便地模拟出同时满足给定高度和长度两方面群性特征要求的不规则波群。在此基础上,给出了在水槽指定位置处产生不规则波群的造波板控制信号计算方法,在实验室成功地模拟了同时满足频谱及群性要求的波浪。此外,分析了波浪在传播过程中群性的变化,结果表明,在进行考虑波浪群性的物理模型实验时,不同于一般随机波浪的实验,需在指定位置处产生满足模拟要求的波浪。

Based on the improved empirical wave envelope spectrum,a method to simulate unidirectional irregular wave groups was developed in this paper.Simulation examples demonstrated that irregular wave groups which included not only its group height but also its length could be conveniently simulated by this empirical wave envelope spectrum,the wave parameters and the parameters for the description of the wave group height and group length were given.Then,the calculation method of the wave maker signals for generating irregular wave groups at a specified position in the wave flume was proposed.Random waves containing expected wave groupiness and wave spectrum were satisfactorily simulated in the laboratory.In addition,the variation of the wave groupiness with the wave propagation was investigated.It shows that the waves with desired wave groupiness should be generated at a specified position in the wave flume for physical model test considering the wave groupiness,which is different from the experiments on the common random waves.