文档介绍：弧面防波堤水动力特性数值分析
Numerical Research on the Hydrodynamic Characteristics of Circular Breakwater
摘要
本论文是在开展弧面防波堤水动力特性的数值模型的基础上完成的。论文首先说明了课题的背景和意义,以及国内外研究现状及分析;然后介绍了垂向二维波浪数学模型理论基础,并详细说明了实现该模型的NEWFLUM软件使用以及编制程序的注意点;最后运用垂向二维波浪数学模型来分析新型弧面防波堤的水动力特性。
本文中的垂向二维波浪数学模型以不可压缩黏性流体雷诺平均的纳维斯托克斯方程(RANS)为控制方程,采用k–ε紊流传输模型封闭雷诺应力项,并采用源函数造波来模拟五阶斯托克斯(Stokes)波对弧面防波堤的作用。通过数模模拟来分析对弧面防波堤的水动力特性(本文主要研究圆弧堤和半圆堤的波面过程,波浪反射、透射特性)。
数模结果表明,圆弧堤和半圆堤的反射透射系数变化规律相同,在堤顶相对超高小于零(淹没堤情况)时,反射系数都随着堤顶相对超高的增大略有减小;在堤顶相对超高大于零(出水堤情况)时,反射系数都随着堤顶相对超高的增大较明显地增大;但它们的递变速率略有不同。而透射系数总体上都随着堤顶相对超高的增大较明显地减小,且圆弧堤透射系数的递减速率略大于半圆堤的透射系数。圆弧堤与半圆堤透射系数相对大小的变化恰好与其反射系数相对大小的变化相反,这与波浪总能量守恒相吻合(总能量=反射波能+透射波能+紊动损耗能量)。最后还比较了圆弧堤和半圆堤的反透射系数变化与相对波高( H/h )、波陡( H/L )大小的关系。
关键词:数值模拟;圆弧面防波堤;半圆型防波堤;水力特性;VOF法;RANS方程;
ABSTRACT
This paper pleted by carrying out the numerical model of the hydrodynamic characteristics of circular breakwater. Firstly, the paper describes the background and significance of the project. Secondly, the vertical two-dimensional wave numerical model is introduced. Then, the implementation and programming attention of the model NEWFLUM software is stated in detail. Finally, the vertical two-dimensional numerical model is used to analyze the hydrodynamic characteristics of the circular wave breakwaters.
The control equations of the vertical two-dimensional wave model are the pressible viscous fluid Reynolds-averaged Navier-Stokes equations (RANS) with k-ε turbulence closure model for Reynolds stress transport items. And the source function method is used to generate the fifth-order Stokes waves in numerical wave flume. Based on the numerical simulations of the circular breakwaters (majored in the quarter-circular breakwater and semi-circular breakwater), the wave surface process, wave reflection and transmission characteristics of both breakwaters are discussed in this paper.
The numerical results show that the reflective and transmittive coefficients are similar. In the cases of submerged breakwaters, the reflection coefficie