数值研究非平底地形对畸形波能量结构的影响

发布时间：2019-01-12 10:28

【摘要】：采用流体体积(VOF)方法捕捉自由表面,结合有限差分方法求解N-S(Navier-Stokes)方程、k-ε模型封闭,建立数值模型,并使用该模型模拟非平底地形条件下畸形波的生成。采用小波分析方法计算模拟结果的时频能量谱,基于计算结果分析非平底地形对畸形波能量集中程度和高频能量的影响。主要结论为:坡度小于1∶10的斜坡地形和无量纲水深变化小于0.333的曲线地形对畸形波时频能量谱的影响不显著;坡度大于1∶10的斜坡地形和无量纲水深变化大于0.333的曲线地形会显著影响畸形波的时频能量谱,随着坡度和无量纲水深变化的增加,时频能量谱中畸形波发生时刻附近,能量向高频方向移动,使得能量在高频端的分布范围增大,时频谱密度峰值减小;斜坡和曲线地形的特征变化对于畸形波能量集中度参数的影响不显著。
[Abstract]:The free surface is captured by the (VOF) method of fluid volume, the N-S (Navier-Stokes) equation is solved by the finite difference method, the k- 蔚 model is closed, and the numerical model is established. The model is used to simulate the generation of deformable waves under the condition of non-flat bottom terrain. The time-frequency energy spectrum of the simulation results is calculated by wavelet analysis method. Based on the calculation results, the influence of non-flat bottom topography on the energy concentration of the deformity wave and the high frequency energy is analyzed. The main conclusions are as follows: slope topography with slope less than 1:10 and curve topography with dimensionless water depth change less than 0.333 have no significant effect on time-frequency energy spectrum of deformities; The slope topography with slope degree greater than 1:10 and the curve terrain with dimensionless water depth change greater than 0.333 will significantly affect the time-frequency energy spectrum of the abnormal wave. With the increase of slope and dimensionless water depth variation, the time of occurrence of the abnormal wave in the time-frequency energy spectrum is near. When the energy moves to the high frequency direction, the distribution range of the energy in the high frequency end increases and the peak value of the time spectrum density decreases. The effects of slope and curve topography on the energy concentration of deformities are not significant.
【作者单位】：交通运输部天津水运工程科学研究所;港口水工建筑技术国家工程实验室;
【基金】：国家自然科学基金项目——量化分析三维畸形波内部结构(51509120)
【分类号】：P731.2

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