不规则波折射的数学模型

A NUMERICAL MODEL FOR REFRACTION OF IRREGULAR WAVES

本文对光易型方向函数中的集中度参数Ｓｍａｘ进行了推算，得到了在不同底坡和入射角情况下，Ｓｍａｘ～ｄ／（Ｌｓ）。的关系曲线，从而较合理地给出了浅水区域的方向谱Ｓ（ｆ，θ）。本文用谱分量的线性迭加法建立了不规则波折射的数值模式，计算了具有各种理论方向谱的不规则波在平行直线状等深线海滩上的折射。其结果得到了不规则波折射系数ｋｓｒ的计算图。将所得的结果与用正弦波求得的值作了比较。另外，本文还探讨了方向谱的分割数与不规则波折射计算精度的关系，并对如何节省计算机时作了研究，从而确定了频率和方向的最佳分割数。

This paper deals with concentrative degree parameter Smax which has been contained in Mitsuyasu's directional effect function. A series of curres about Smax over d/(Ls)0 at different angles of incidence and different bottom slopes have been obtained, thereby, directional wave spectrums S(f,θ) in shallow water have been given reasonably. By means of linear superposition for component waves of spectrum, a mathematical scheme has been developed to calculate refraction of irregular waves which possessed various theoretical directional wave spectrums. For a straight coastline with a uniform bottom slope, we got some calcalating diagrams about irregular wave s refractive coefficient ksr. The suitable range of regular waves and irregular waves are compared. In addition, the paper talks about the relation between numbers that spectrum has been cut apart and calculating precision of irregular wave refraction, and studies how to save computer time, thus determining optimum numbers of freguency and direction which should be cut apart.