Modeling of the Mixture of Wastewater Discharged from A Submerged Multiport Diffuser in Nantong Sea-Area     

王超  王沛芳 《中国海洋工程》2005,19(1):97-110

Laboratory experiments were conducted to investigate the mixture of wastewater discharged from a submerged multiport diffuser in the Nantong sea-area. The process was then simulated with a three-dimensional numerical model. The plane or line patch was used to impose the discharge momentum flux in the near field. A comparison of model simulation with laboratory experiments shows that the proposed model can be used to simulate the shapes of pollution plumes, the distributions of excess concentration, and the velocity induced by a coflowing diffuser in proximity to a shoreline boundary. From the numerical simulation and laboratory experiments, it is recommended that the multiport diffuser be placed in a hydrodynamically active sea-area.  相似文献   

On the Range of Validity and Accuracy of Boussinesq-Type Models     

许泰文杨炳达  曾以帆 《中国海洋工程》2004,18(1):93-106

In this paper the range of validity and comparison of accuracy of three Boussinesq-type models (Madsen and Sφrensen, 1992; Nwogu, 1993; Wei et al., 1995; referred to as MS, NW and WKGS, respectively) are analyzed and discussed. The governing equations are extended to the second-order approximations to keep higher-order nonlinear terms. Two key parameters ε and μ representing wave nonlinear and frequency dispersive properties are used to demarcate the limit of applicability for these three models. The accuracy of predictions by each model is compared by the relative errors with and without hlgher-order nonlinear terms in Boussinesq equations. A numerical model is developed based on one-dimensional Boussinesq equations and applied to the case of waves propagating over a submerged bar. The performance and feasibility of each model are tested against laboratory data.  相似文献   

Numerical Simulation of Hydrodynamic Behaviors of Gravity Cage in Waves     

赵云鹏李玉成  董国海桂福坤 《中国海洋工程》2007,21(2):225-238

This paper aims at investigation of the dynamic properties of gravity cage exposed to waves by use of a numerical model. The numerical model is developed, based on lumped mass method to set up the equations of motion of the whole cage; meanwhile the solutions of equations are solved by the Runge-Kutta-Verner fifth-order and sixth-order method. Physical model tests have been carried out to examine the validity of the numerical model. The results by the numerical simulation agree well with the experimental data.  相似文献   

磁偏角变化对垂直分量磁变仪记录影响的实验     

朱兆才 《地震学刊》1995,(1):63-65

实验证实了磁偏角变化对垂直分量磁变仪记录有影响。对于磁南北向布局中的垂直分量磁变仪，Ｚ磁针偏离定向位置θ０＝０越远，磁偏角变化对垂直分量磁变仪记录的影响越大。认为应重视垂直分量磁变仪遥定向工作并有必要提高垂直分量磁变仪磁针稳定性。  相似文献   

对“磁暴短周期感应场和佘山地区地幔电导率”一文的讨论          下载免费PDF全文

陈伯舫 《地球物理学报》1983,26(3):295-298

本文以理论公式证明地磁测深的电磁阻抗不可能在某一“穿透频率”附近发生不连续的突变。利用“穿透频率”的概念定出的佘山地区地幔电导率是不妥的。  相似文献   

用地质罗盘代替悬挂罗盘仪测量天井方位角     

《河南测绘》2006,(1):27-28

  相似文献   

DEPTH-AVERAGED 2-D CALCULATION OF TIDAL FLOW,SALINITY AND COHESIVE SEDIMENT TRANSPORT IN ESTUARIES     

WeimingWU SamS.Y.WANG 《国际泥沙研究》2004,19(3):172-190

A depth-averaged 2-D numerical model for unsteady flow, salinity and cohesive sediment transport in estuaries is established using the finite volume method on the non-staggered, curvilinear grid. The convection terms are discretized by upwind schemes, the diffusion terms are by the central difference scheme, and the time derivative terms are by the three-time-level implicit scheme. The coupling of flow velocity and water level in the 2-D shallow water equations is achieved by the SIMPLEC algorithm with the Rhie and Chow‘s momentum interpolation method. The sediment model calculates the settling, deposition, erosion and transport of cohesive sediment, taking into account the influence of sediment size, sediment concentration, salinity and turbulence intensity on the flocculation of cohesive sediment. The flow model is first tested against the measurement data in the Tokyo Bay and San Francisco Bay, showing good agreements. And then, the entire model of flow, salinity and sediment transport is verified in the Gironde Estuary. The water elevation, flow velocity, salinity and sediment concentration are well predicted.  相似文献   

地磁场H、D受HVDC输电干扰特征分析          下载免费PDF全文

林秀娜  曲保安  范晓勇  陈洪凯  于庆民  赵银刚 《地球物理学报》1954,63(10):3818-3826

以受宁东线高压直流（HVDC）输电干扰相对严重的11个地磁台站为主要研究对象,以蒙城台为干扰幅度量取的参考台站,研究了地磁场水平分量H、磁偏角D受HVDC输电的干扰特征.发现H和D受HVDC输电干扰具有同步性和偏向性;同一HVDC输电线路两侧H和D干扰幅度具有线性关系,但线性关系明显弱于垂直分量Z干扰幅度的比例关系;接地极附近台站各自的Z、H、D干扰幅度具有线性关系.之后对H和D干扰产生的机理进行了深入的定性分析.根据得到的干扰特征的结论,提出了以红山台Z、H、D为输入的本研究相关台站的Z、H、D为输出的自动计算方法.经过误差分析,本方法平均误差水平低于国家地磁学科中心当前使用算法误差水平,最高降幅达42.9%.  相似文献   

土地利用动态变化的空间测算模型研究   总被引：1，自引：0，他引：1  

张新长  潘琼  赵元 《地理学报(英文版)》2004,14(3):359-365

The spatial calculating analysis model is based on GIS overlay. It will compartmentalize the land in research district into three spatial types: unchanged parts, converted parts and increased parts.By this method we can evaluate the numerical model and dynamic degree model for calculating land-use change rates. Furthermore, the paper raises the possibility of revising the calculating analysis model of spatial information in order to predicate more precisely the dynamic changing level of all types of land uses. In the most concrete terms, the model is used mainly to understand changed area and changed rates (increasing or decreasing) of different land types from microcosmic angle and establish spatial distribution and spatio-temporal principles of the changing urban lands. And we will try to find out why the situation can take place by combining social and economic situations. The result indicates the calculating analysis model of spatial information can derive more accurate procedure of spatial transference and increase of all kinds of land from microcosmic angle. By this model and technology we can conduct the research of land-use spatio-temporal structure evolution more systematically and more deeply, and can obtain a satisfactory result. The result will benefit the rational planning and management of urban land use of developed coastal areas in China in the future.  相似文献   

A numerical model of coastline deformation for sandy beach at downstream of a jetty     

SUN Linyun  PAN Junning  XING Fu  LIU Jiaju 《海洋学报(英文版)》2004,23(1):169-178

A reformed numerical model based on the “one-line theory” for beach deformation is presented. In this model, the change of beach slope during coastline procession is considered.A wave numerical model combined with wave refraction, diffraction and reflection is used to simulate wave climate to increase numerical accuracy.The results show that the numerical model has a good precision based on the adequate field data. The results can be applied to practical engineering.  相似文献