检索结果-南通市图书馆

A trigonometric series expansion method for the Orr-Sommerfeld equation

Applied Mathematics and Mechanics(English Edition) 2019年第6期40卷 877-888页

作者： Ying TAN Weidong SU State Key Laboratory for Turbulence and Complex Systems Peking UniversityBeijing 100871China Department of Mechanics and Engineering Science College of EngineeringPeking UniversityBeijing 100871China

A trigonometric series expansion method and two similar modified methods for the Orr-Sommerfeld equation are presented. These methods use the trigonometric series expansion with an auxiliary function added to the highest order derivative of the unknown function and generate the lower order derivatives through successive integra- tions. The proposed methods are easy to implement because of the simplicity of the chosen basis functions. By solving the plane Poiseuille flow (PPF), plane Couette flow (PCF), and Blasius boundary layer flow with several homogeneous boundary conditions, it is shown that these methods yield results with the same accuracy as that given by the conventional Chebyshev collocation method but with better robustness, and that ob- tained by the finite difference method but with fewer modal number.

关键词： Orr-Sommerfeld equation spectral method trigonometric function parallel shear flow hydrodynamical stability eigenvalue problem

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

NUMERICAL STUDY OF WAVE EFFECTS ON SURFACE WIND STRESS AND SURFACE MIXING LENGTH BY THREE-DIMENSIONAL CIRCULATION MODELING

引用

Journal of Hydrodynamics 2006年第4期18卷 397-404页

作者： LIANG Bing-chen LI Hua-jun LEE Dong-yong Engineering College Ocean University of China Qingdao 266071 China Researcher Coastal and Harbour Engineering Research CenterKorea Ocean Research and Development Institute Ansan Korea

The effects of waves on Surface Drag Coefficient （SDC） and surface mixing length were analyzed and discussed by carrying out three-dimensional current modeling for the Bohai Sea in the present work. A threedimensional coupled hydrodynamical-ecological model for regional and shelf seas （COHERENS） incorporating the influences of wave-current interactions was coupled with the third-generation wave model swan taking into account time-varying currents. The effects of waves on currents were included in the SDC, surface mixing length and bottom drag coefficient. Firstly, the formulations in Donelan were incorporated into the COHERENS to account for wave-dependent SDC. In order to compare simulation results for the wave-dependent SDC, the simulation for wind-dependent SDC was also carried out. Second, Wave-Induced Surface Mixing Length （described as WISML sometimes in this paper） was incorporated into the COHERENS. Four numerical experiments were conducted to discuss the effects of two kinds of wave processes. Generally, the values of time series of current velocity and water surface elevation given by the simulation with all of the three wave processes have a good agreement with observed data. The existence of WISML changes obviously current vertical profiles and the existence of the wave dependent SDC modifies the current field of both top and bottom layers with the wind-dependent SDC.

关键词： Bohai hydrodynamical COHERENS waves,currents swan mixing length wind stress

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Influence of the Freshwater Discharge on the Hydrodynamics of Patos Lagoon, Brazil

引用

International Journal of Geosciences 2014年第9期5卷 925-942页

作者： Gustavo Pessoa de Barros Wiliam Correa Marques Eduardo de Paula Kirinus Institute of Mathematics Statistics and Physics Federal University of Rio Grande Rio Grande Brazil Institute of Oceanography Federal University of Rio Grande Rio Grande Brazil

Patos Lagoon is a very dynamic environment presenting hydrodynamic fluctuations from synoptic to decadal timescales. Thus, understanding the processes that determine the long term variability is fundamental for the correct coastal planning and management of this region. The main objective of this study is to understand how the freshwater discharge of the main tributaries controls the estuarine hydrodynamics of the Patos Lagoon, when considering long term timescales. Two numerical simulations were carried out using the TELEMAC3D numerical model, the former using freshwater discharge from 1940 to 1973 year (simulation A), and the second simulation using data between 1974 and 2006 year (simulation B). These two periods were selected because before (after) 1973 year, the annual mean freshwater discharge was lower (higher) than the mean value for the whole period (1080 m3/s). The navigational channel discharge, water level, salinity and current velocity differences between both simulations were analyzed. Ebb conditions prevailed over flood conditions for both simulations, but simulation B presented a higher volume of freshwater exported through the coastal zone. Water level differences demonstrated higher values (0.08 meters) close to the Guaiba River, which is the main tributary of the study region, and lower values were observed near to the Patos Lagoon mouth (0 meters). The most significant differences in the mean bottom and surface salinity were observed in the central zone of the estuary and at the Barra Breakwaters. Simulation A presented higher saline intrusion due to lower freshwater discharge, while simulation B showed an increase in the coastal plume intensity, caused by the higher freshwater discharge. The hydrodynamical simulations demonstrated with precision that the freshwater discharge intensity determine the vertical stratification of the estuary.

关键词： Estuarine Hydrodynamics Freshwater Discharge hydrodynamical Modeling

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A Process Study of the Wind-Induced Circulation in the Persian Gulf

引用

Open Journal of Marine Science 2013年第1期3卷 1-11页

作者： Stéphane Pous Xavier Carton Pascal Lazure Ifremer Brest France Université de Bretagne Occidentale Brest France Université Pierre et Marie Curie Paris France

A shallow-water model, coupled with a three dimensional, hydrostatic ocean model, is used to study the wind induced circulation, and the Shatt-al-Arab river plume expansion, in the Persian Gulf. The models are used in an idealized configuration. The following results are obtained: 1) with northwesterly winds, a double gyre is formed: this gyre is cyclonic in the south and anticyclonic in the north. Southeastward currents flow along the Iranian and Arabian coast where the wind stress at the surface dominates the pressure gradient related to the free surface slope, and conversely in the deeper region of the Gulf;2) In the eastern part of the Gulf, the cyclonic gyre intensifies, as observed and reported in the literature;3) For northwesterly winds, the plume from Shatt-al-Arab first heads towards the Iranian coast and then spreads southeastward along the Arabian coast;for northerly and northeasterly winds, the plume directly follows the Kuwaiti coast and then the Arabian coast. This sensitivity of the orientation can be related to the double gyre flow structure;4) A southeasterly wind confines the plume in the northern end of the Gulf as does a pure tidal flow.

关键词： Persian Gulf Wind-Induced Circulation hydrodynamical Modeling

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A Process Study of the Tidal Circulation in the Persian Gulf

引用

Open Journal of Marine Science 2012年第4期2卷 131-140页

作者： Stéphane Pous Xavier Carton Pascal Lazure DYNECO IFREMER Brest France LOCEAN/IPSL Université Pierre et Marie Curie Paris France LPO/IUEM Université de Bretagne Occidentale Brest France

A homogeneous shallow-water model with free surface is used to model the tidal circulation in the Persian Gulf. The numerical finite-difference model includes harmonic diffusion of horizontal momentum and quadratic bottom friction, it has a 9 km mesh size and it is forced by 7 tidal components at its southern boundary. High precision bathymetric data are used to obtain the bottom topography. The numerical model is run for more than a year. The results are the following: 1) The model accurately reproduces the tidal phase and amplitude observed at 42 tidal gauges in the region. This accuracy is attributed to the presence of the 7 components which are able to interact nonlinearly;2) The amphidromic points are also well positioned by the model due to a proper choice of bathymetry. This was checked also with a simpler geometry of the domain;3) The tidal currents can be strong in the Straits of Hormuz and in shallow areas;thus they will have an effect of the hydrology of the region. The residual currents are weak so that they will be negligible for the large-scale circulation on long periods;4) Finally, the sea-surface elevation forecast by the model is in close agreement with in-situ measurements of pressure in the Straits, performed during the GOGP99 experiment.

关键词： Persian Gulf Barotropic Tide hydrodynamical Modeling Comparison with Data

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：