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就二维浅水体动力方程应用物理意义明确的有限体积法，收敛快而稳定的五对角全隐格式，以及嵌套，变步长的网格和动边界技术，进行二维海流场的数值计算，并研究了开边界为斜断面的定解条件的数值方法和开边界上断面各点水位的计算方法。最后把本数值方法应用于某海岸工程的可行性研究，并验证了这种海流数值计算方法的合理性。 相似文献
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海岸河口三维潮流数学模型 总被引：1，自引：0，他引：1
本文采用有限元法建立了适用于海岸河口浅水地区的三维潮流数学模型，垂向采用绝对分层坐标系统，将整个水柱分成若干层，在每层内通过垂向积分平均，将三维问题简化为多个平面二维问题。在求解有限元方程中，引入集中质量矩阵技术，在时间上采用两步ＬａｘＷｅｎｄｒｏｆｆ格式，使有限元方程直接以显式解出，不需联立求解，节省了大量的计算时间和计算内存，通过模拟表面切应力作用在矩形水地上而引起的水流，计算结果与分析解比较一致，并将本模型应用到香港维多利亚水道中，计算结果与实测值亦符合较好，证明本模型是一个实用而有效的三维潮流数学模型。 相似文献
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就二维浅水流体动力方程应用物理意义明确的有限体积法，收敛快而稳定的五对角全隐格式，以及嵌套、变步长的网格和动边界技术，进行二维海流场的数值计算，并研究了开边界为斜断面的定解条件的数值方法和开边界上断面各点水位的计算方法。最后把本数值方法应用于某海岸工程的可行性研究，并验证了这种海流数值计算方法的合理性。 相似文献
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日照港煤码头浚深工程回淤分析 总被引：3，自引：0，他引：3
采用水动力学三维数学模型对日照港煤码头水域的水动力因素进行了计算,并在此基础上对煤码头浚深工程实施后港池和航道回淤进行了计算分析.计算结果与实测结果比较表明:文中模型较好地重演日照港煤码头水域潮流场,对于港池与航道的回淤分析合理可靠. 相似文献
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河口三维流动数学模型研究进展 总被引：16，自引：2，他引：14
回顾了近年来国内外河口与海岸三维水动力学数学模型研究的新进展,着重讨论了三维水动力学数学模型研究中的若干基本问题。对河口三维潮流和密度流问题而言,其基本方程已经基本解决,但是在风暴侵袭期间,多种尺度的动力因素同时存在,建立其合理的流动模型是一项重要的基础性工作;尽管已有一些成功的河口三维流动数学模型,但是寻求基于并行计算技术的数值模拟系统将是值得努力的方向。此外,河口大规模动边界和漫滩水流的模拟仍有待作进一步研究。 相似文献
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采用ADI的有限差分方法对不可压缩流体二维浅水环流方程离散和求解,建立水动力数学模型,用迎风格式离散赤潮生物动力学方程,通过水动力学和生物动力学相结合的方法,建立了二维赤潮生态数学模型。将所建立的二维赤潮生态数学模型应用于渤海,针对渤海海域2004年6月11～16日发生的棕囊藻赤潮进行了数值计算。对EOS/MODIS卫星拍摄的2004年6月份的渤海海区卫星遥感图像进行了处理,提取出海水中的赤潮信息,并计算出赤潮面积,使其与模型计算出的赤潮面积进行对比验证,结果基本吻合,表明该模型能够较好地模拟赤潮的生消过程,为渤海地区的赤潮预报提供了科学依据。 相似文献
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系泊船非线性波浪力时域计算: 二维模型 总被引：6，自引：1，他引：6
为找到具有工程实用价值的港口系泊船波浪力的时域计算方法,建立了在港口中存在系泊船时非线性波浪力时域计算的垂直二维耦合模型:用Boussinesq方程计算船的两侧的外域,用欧拉方程计算船底面下的内域,两域在交界面处的连接条件是流量连续和压力相等.将复平面内的边界元方法应用于所研究问题,对耦合模型进行了验证.进行了相关模型实验,实验结果与数值计算结果比较表明这两种数值计算模型都具有满意的精度,但耦合模型的计算效率要远远高于边界元方法的计算效率.本耦合模型的数学处理简单,可适用于工程计算. 相似文献
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Lin Liang-Fu Hsu Ho-Han Liu Char-Shine Chao Kuo-Han Ko Chia-Chun Chiu Shye-Dong Hsieh Hsin-Sung Ma Yu-Fang Chen Song-Chuen 《Marine Geophysical Researches》2019,40(4):619-633
Marine Geophysical Research - Strong ocean current influences a marine seismic survey and forces the streamer off-course from the survey line. The sideway drift of the streamer results in that the... 相似文献
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Studying complex pore structures is the key to understanding the mechanism of shale gas accumulation. FIB-SEM (focused ion beam-scanning electron microscope) is the mainstream and effective instrument for imaging nanopores in gas shales. Based on this technology, 2D and 3D characteristics of shale samples from Lower Silurian Longmaxi formation in southern Sichuan Basin were investigated. 2D experimental results show that the pores in shale are nanometer-sized, and the structure of those nanopores can be classified into three types: organic pores, inorganic pores and micro fractures. Among the three types, organic pores are dominantly developed in the OM (organic matter) with three patterns such as continuous distributed OM, OM between clay minerals and OM between pyrite particles, and the size of organic pores range from 5 nm to 200 nm.Inveresly, inorganic pores and micro fractures are less developed in the Longmaxi shales. 3D digital rocks were reconstructed and segmented by 600 continuous images by FIB cutting and SEM imaging simultaneously. The pore size distribution and porosity can be calculated by this 3D digital core, showing that its average value is 32 nm and porosity is 3.62%.The 3D digital porosity is higher than its helium porosity, which can be regarded as one important parameter for evaluation of shale gas reserves. The 2D and 3D characterized results suggest that the nanometer-sized pores in organic matter take up the fundamental storage space for the Longmaxi shale. These characteristics have contributed to the preservation of shale gas in this complex tectonic area. 相似文献
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Based on recent experiments carried out in wave basin on breakwaters with armour layer of rocks and cubes, this paper examines the dependence of the reflection coefficient on wave directional spreading and obliquity. Results suggest that long-crested and short-crested waves give similar reflection. The reflection coefficient is markedly dependent on the wave angle of incidence. The performance of formulae available in the literature is checked against the new dataset and a significant improvement is proposed by including the wave obliquity factor that appears in the traditional expression for the overtopping discharge. 相似文献
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Predictions of nearshore and surf zone processes are important for determining coastal circulation, impacts of storms, navigation, and recreational safety. Numerical modeling of these systems facilitates advancements in our understanding of coastal changes and can provide predictive capabilities for resource managers. There exists many nearshore coastal circulation models, however they are mostly limited or typically only applied as depth integrated models. SHORECIRC is an established surf zone circulation model that is quasi-3D to allow the effect of the variability in the vertical structure of the currents while maintaining the computational advantage of a 2DH model. Here we compare SHORECIRC to ROMS, a fully 3D ocean circulation model which now includes a three dimensional formulation for the wave-driven flows. We compare the models with three different test applications for: (i) spectral waves approaching a plane beach with an oblique angle of incidence; (ii) monochromatic waves driving longshore currents in a laboratory basin; and (iii) monochromatic waves on a barred beach with rip channels in a laboratory basin. Results identify that the models are very similar for the depth integrated flows and qualitatively consistent for the vertically varying components. The differences are primarily the result of the vertically varying radiation stress utilized by ROMS and the utilization of long wave theory for the radiation stress formulation in vertical varying momentum balance by SHORECIRC. The quasi-3D model is faster, however the applicability of the fully 3D model allows it to extend over a broader range of processes, temporal, and spatial scales. 相似文献
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1997年3月在日本冲绳县那霸市召开了“第二次海底电缆应用国际会议”。美国华盛顿大学两名海洋科学工作者John Delaney和Bruce Howe参加了这次会议。前者由于发现了在海底热水带在光合作用下而能生活的生物,因此成为有名的海洋地质学者;后者是首次获得海洋声波层析成像的学者。日本近十年来积极倡导海底电缆的4D观测,在此领域世界领先。日本在1997年1月17日,应用1964年日本和美国间铺设的最早国际海底电缆。TPC-1和距东京400km的南伊豆小笠原的海底电缆设置了世界最早的海底地震站, 相似文献
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In this study, 1D and 2D shallow-water models were coupled to simulate unsteady flow in channel networks and embayment. The 1D model solved the 1D shallow-water equations (St. Venant) using the Preissmann box method and targeted long narrow reaches of the river networks, while the 2D model targeted broad channels and embayment and solved the 2D shallow-water equations using a semi-implicit scheme applied to an unstructured grid of triangular cells. The 1D and 2D models were solved simultaneously by building a matrix for the free surface elevation at every 1D junction and 2D cell center. Velocities were then computed explicitly based on the results at the previous time step and the updated water level. The originality of the scheme arose from a novel coupling method. The results showed that the coupled 1D/2D model produced identical results as the full 2D model in classical to benchmark problems with considerable savings in computational effort. Application of the model to the Pearl River Estuary in southern China showed that complex patterns of tidal wave propagation could be efficiently modeled. 相似文献
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《Coastal Engineering》2005,52(8):691-707
Existing methods for solving 1D morphodynamical systems have been reviewed and new, improved approaches have been identified. Usually the flow equations and the bed-updating equation are solved at separate time steps, using a quasi-steady approach. In this paper we have investigated the simultaneous (or coupled) solution of the equations. The schemes tested are the Lax–Wendroff and the Roe schemes, both with and without flux-limiting methods. Furthermore the discretisation of source terms has been investigated and has shown to be important. 相似文献