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在潮汐河口地区,由于地形的变化以及水流和波浪的相互作用,而导致流速场和波场产生变化。本文利用时均的连续方程、动量方程和考虑波浪折射和绕射的波动方程,建立了求解流速场和波面变化的数值模型。根据以往的结果和实验对上述模式进行了验证,取得了较为理想的结果。 相似文献
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Study on the Log-Linear Velocity Profile of Near-Bed Tidal Current in Estuarine and Coastal Waters 总被引:2,自引:1,他引:2
Many observed data show that the near-bed tidal velocity profile deviates from the usual logarithmic law. The amount of deviation may not be large, but it results in large errors when the logarithmic velocity profile is used to calculate the bed roughness height and friction velocity (or shear stress). Based on their investigation, Kuo et al. (1996) indicate that the deviation amplitude may exceed 100%. On the basis of fluid dynamic principle, the profile of the near-bed tidal velocity in estuarine and coastal waters is established by introducing Prandtl' s mixing length theory and Von Kannan selfsimilarity theory. By the fitting and calculation of the near-bed velocity profde data observed in the west Solent, England, the results are compared with those of the usual logarithmic model, and it is shown that the present near-bed tidal velocity profile model has such advantages as higher fitting precision, and better inner consistency between the roughness height and friction velocity. The calculated roughness height and friction velocity are closer to reality. The conclusions are validated that the logarithmic model underestimates the roughness height and friction velocity during tidal acceleration and overestimates them during tidal deceleration. 相似文献
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Based on a coupled hydrodynamic-ecological model for regional and shelf seas (COHERENS), a three-dimensional baroclinic model
for the Changjiang (Yangtze) River estuary and the adjacent sea area was established using the sigma-coordinate in the vertical
direction and spherical coordinate in the horizontal direction. In the study, changing-grid technology and the “dry-wet” method
were designed to deal with the moving boundary. The minimum water depth limit condition was introduced for numerical simulation
stability and to avoid producing negative depths in the shallow water areas. Using the Eulerian transport approaches included
in COHERENS for the advection and dispersion of dissolved pollutants, numerical simulation of dissolved pollutant transport
and diffusion in the Changjiang River estuary were carried out. The mass centre track of dissolved pollutants released from
outlets in the south branch of the Changjiang River estuary water course has the characteristic of reverse current motion
in the inner water course and clockwise motion offshore. In the transition area, water transport is a combination of the two
types of motion. In a sewage-discharge numerical experiment, it is found that there are mainly two kinds of pollution distribution
forms: one is a single nuclear structure and the other is a double nuclear (dinuclear) structure in the turbid zone of the
Changjiang River estuary. The rate of expansion of the dissolved pollutant distribution decreased gradually. The results of
the numerical experiment indicate that the maximum turbid zone of the Changjiang River estuary is also the zone enriched with
pollutants. Backward pollutant flow occurs in the north branch of the estuary, which is similar to the backward salt water
flow, and the backward flow of pollutants released upstream is more obvious. 相似文献
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台湾岛地处亚欧大陆和太平洋交界处,台风、东北季风等所引起的海洋灾害频繁,所以建立完备的海洋水文观测体系显得尤为重要。中国台湾自主建置完成的近海水文观测体系由资料浮标站、观测桩、潮位站、岸边气象站、雷达测波站等多种近海水文观测系统构建组成;同时,为确保观测体系的准确性和规范性,还建立了数据品质管理系统和标准化作业模式。在近海水文观测数据的分析方面,尝试应用新的数学分析方法,如通过EMD(empirical mode decomposition)方法探讨风暴潮水位变化,利用小波转换从雷达观测影像中分析近岸波浪信息,以及发展数据同化技术将观测数据应用于作业化波浪现报、预报模式。此外,近海水文观测体系在社会应用方面有着很大的发展潜质。 相似文献
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潮流计算结果的可视化 总被引:8,自引:0,他引:8
浓度应用Matlab语言进行潮流数值计算结果的可视化研究,取得初步成功。通过对长江口三维数值模计算结果的可视化实践,表明Matlab语言具有卓越的可视化能力,籍此,动画制作流程更简单,图形显示技术更先进,可视化结果更副真。 相似文献