A Compact Explicit Difference Scheme of High Accuracy for Extended Boussinesq Equations     

周俊陶林建国  谢志华 《中国海洋工程》2007,21(3):507-514

Presented here is a compact explicit difference scheme of high accuracy for solving the extended Boussinesq equations.For time discretization,a three-stage explicit Runge-Kutta method with TVD property is used at predicting stage,a cubic spline function is adopted at correcting stage,which made the time discretization accuracy up to fourth order;For spatial discretization,a three-point explicit compact difference scheme with arbitrary order accuracy is employed.The extended Boussinesq equations derived by Beji and Nadaoka are solved by the proposed scheme.The numerical results agree well with the experimental data.At the same time,the comparisons of the two numerical results between the present scheme and low accuracy difference method are made,which further show the necessity of using high accuracy scheme to solve the extended Boussinesq equations.As a valid sample,the wave propagation on the rectangular step is formulated by the present scheme,the modelled results are in better agreement with the experimental data than those of Kittitanasuan.  相似文献   

A new efficient 3D non-hydrostatic free-surface flow model for simulating water wave motions     

Doo Yong Choi  Chin H. Wu   《Ocean Engineering》2006,33(5-6):587-609

A new three-dimensional, non-hydrostatic free surface flow model is presented. For simulating water wave motions over uneven bottoms, the model employs an explicit project method on a Cartesian the staggered gird system to solve the complete three-dimensional Navier–Stokes equations. A bi-conjugated gradient method with a pre-conditioning procedure is used to solve the resulting matrix system. The model is capable of resolving non-hydrostatic pressure by incorporating the integral method of the top-layer pressure treatment, and predicting wave propagation and interaction over irregular bottom by including a partial bottom-cell treatment. Four examples of surface wave propagation are used to demonstrate the capability of the model. Using a small of vertical layers (e.g. 2–3 layers), it is shown that the model could effectively and accurately resolve wave shoaling, non-linearity, dispersion, fission, refraction, and diffraction phenomena.  相似文献   

Second-order resonance of sloshing in a tank     

G.X. Wu   《Ocean Engineering》2007,34(17-18):2345-2349

Sloshing in a two-dimensional rectangular tank in horizontal motion is analysed based on the velocity potential theory. It is found that even when the first-order excitation is away from all the natural frequencies of the tank, second-order resonance can still occur when the sum-frequency or the difference-frequency is equal to one of the natural frequencies corresponding to the even mode. However, such resonance is not excited when the sum or difference frequency is equal to the natural frequency of an odd mode.  相似文献   

Post-Miocene stratigraphy and depositional environments of valley-fill sequences at the mouth of Tampa Bay, Florida     

Thomas W. Ferguson  Richard A. Davis  Jr.   《Marine Geology》2003,200(1-4):157-170

Post-Miocene sea-level low stands allowed rivers and karst processes to incise the exposed carbonate platform along the Gulf Coast of Florida. Few Miocene to mid-Pleistocene deposits survived erosion along the present coast except within incised valleys. Since their formation, these valleys have been filled and incised multiple times in response to sea-level changes. The thick sedimentary sequences underlying the mouth of Tampa Bay have been recorded as a range of depositional environments and multiple sea-level incursions and excursions during pre-Holocene time and subsequent to the accumulation of the Miocene carbonate sequences. Sediment analysis of cores collected from a north–south transect across the mouth of Tampa Bay has enabled the identification of lithofacies, ranging from well-sorted, quartz sand to dense, fossiliferous, phosphatic grainstone. These facies were deposited in freshwater, estuarine, and shallow, open marine environments. As a result of channel development and migration within the paleovalley, and cut-and-fill associated with individual transgressions and regressions, correlation of the lithofacies does not extend across the entire transect. Fining-upward sequences truncated by tidal ravinement surfaces that extend throughout the paleovalley can, however, be identified. Age determinations based on 14-C analysis, amino-acid racemization, and strontium isotope analysis dating of numerous samples yield ages of Miocene, Pliocene, early Pleistocene, and late Pleistocene, as well as Holocene for sequences that accumulated and were preserved in this valley-fill complex. Numerous inconsistencies in the stratigraphic organization of the age determinations indicate that there are bad dates, considerable reworking of shells that were dated, or both. For this reason as well as the lack of detailed correlation among the three relatively complete cores, it is not possible to place these strata in a sequence stratigraphic framework.  相似文献   

北部湾三维风生流及密度流模拟   总被引：16，自引：0，他引：16  

夏华永  李树华  侍茂崇 《海洋学报》2001,23(6):11-23

将Casulli差分格式引入三维物理海洋模型计算，模拟了北部湾风生流及密度流。模拟结果表明，夏季西南季风在北部湾导致一个顺时针环流，夏季海水密度梯度导致一个逆时针方向的环流，密度流明显强于风生流；冬季东北寒潮导致一个逆时针环流。模拟结果不支持北部湾夏季为一顺时针环流、冬季为逆时针环流的传统结论，而支持终年为逆时针环流的观点。  相似文献   

Numerical Simulation of Wave Field near Submerged Bars by PLIC-VOF Model   总被引：2，自引：1，他引：2  

刘诚刘晓平  蒋昌波 《中国海洋工程》2005,19(3):509-518

Investigating the wave field near structures in coastal and offshore engineering is of increasing significance. In the present study, simulation is done of the wave profile and flow field for waves propagating over submerged bars, using PLIC-VOF （Pieeewise Linear Interface Construction） to trace the free surface of wave and finite difference method to solve vertical 2D Navier-Stokes （N-S） equations. A comparison of the numerical results for two kinds of submerged bars with the experimental ones shows that the PLIC-VOF model used in this study is effective and can compute the wave field precisely.  相似文献   

低分子量肝素的制备及其结构与活性差异(英文)     

于广利  管华诗  徐家敏  王群 《中国海洋大学学报(自然科学版)》2001,31(5):673-680

低分子肝素作为一种抗血栓的多糖药物在临床中已应用了二十多年 ,目前已作为外科预防血栓形成药物 ,并在治疗急性静脉栓塞紊乱方面取代了未分级肝素。因肝素的来源和制备的方法不同使低分子肝素的精细结构不同 ,低分子肝素结构的复杂性 ,使得各产品的生物活性 ,例如抗蛋白酶活性不同 ,从而导致其临床使用的标准不同。该文将对低分子肝素的制备方法及其结构和抗蛋白酶活性的差异进行报导  相似文献   

泉州湾海域表层沉积物矿物碎屑分布特征及其环境意义   总被引：4，自引：0，他引：4  

谷东起  边淑华  胡泽建  张绪良 《海岸工程》2003,22(2):22-30

对泉州湾13个表层沉积物样品进行了矿物碎屑定量分析．通过矿物分析，发现泉州湾不同站位的轻、重矿物组分、含量和表征存在差异．根据矿物的分布和组合特征．将耒州湾划分为4个组合区，不同组合区所处沉积环境是不同的．分析表明，研完区表层沉积物的碎屑矿物具有明显的亲陆性，物质来源主要为河流输砂和沿湾海岸侵蚀来砂，且其分布受物源、水动力条件和矿物物理性质等因素所控制。  相似文献   

南海北缘东部盆地油气资源研究   总被引：5，自引：0，他引：5  

杜德莉  王树民  陈弘  陈泓君  万玲 《海洋地质与第四纪地质》2001,21(3):67-74

南海北缘东部的珠江口盆地及台西南盆地蕴藏着十分丰富的油气资源，根据区域构造背景、盆地发育分布的特点及中、新生代的油气地质条件，结合含油气构造、油气田、油气井的分布规律，利用油气资源评价的理论、方法，对区内的油气资源进行了综合研究，并按照油气资源状况划分出油气富集区、油气潜力区、油气远景区，在此基础上，再进一步划分出4条油气富集带、11条油气潜力带、8条油气远景带，充分显示了该区石油、天然气的分布规律和油气地质特点，为商业性的勘探开发和理论研究奠定了基础。  相似文献   

磁通门罗盘的原理     

王文彬  程彦秋 《海洋技术学报》1992,11(2):21-27

磁通门罗盘是一种新型罗盘。此罗盘的关键部件是探头,探头主要是由高导磁的软磁材料做成的磁环和线圈组成。当在初级线圈加上交变的激励信号时,即可得到与次级线圈在地磁场中相对应的磁方位角。本文介绍其原理,并对其进行了理论分析。  相似文献