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1.
渤海湾流场以及污染物分布的数值模拟研究   总被引:21,自引:2,他引:19  
以了弄清渤海湾这一具有广阔潮间带典型海域的潮流以及污染物分布状况,采用考虑“窄缝”的二维动边界潮流和对流对涝海湾流场以及污染物分布的浓度场进行了数值模拟研究并应用潮流以及污染物分布的实测模型进行了验证,数值模拟结果与实测符合良好。  相似文献   

2.
本文用差分有限元法对大连湾的潮流场及污染物扩散的浓度场做了数值模拟,其结果对环境评价提供了有益的依据。  相似文献   

3.
大鹏湾潮流场的数值模拟   总被引:1,自引:1,他引:1  
詹小涌 《海洋与湖沼》1989,20(2):149-155
本文根据描述潮流运动变化的连续方程和运动方程,用ADI方法建立差分方程,对大鹏湾潮流场进行了数值模拟;从而根据数值模拟结果和实测结果,对大鹏湾的潮流和潮汐余流等进行了讨论。  相似文献   

4.
采用平面二维水动力及污染物输运模型.针对研究海域的水动力特性.应用潮流场作为背景场驱动控制污染物浓度的对流扩散方程,利用有限元方法对苏北辐射沙洲海域大、中、小潮水动力特征及如东洋口港附近污染物输运进行了计算分析。计算结果与实测结果比较表明:计算所得潮流场合理.辐射沙洲区部分潮流脊间水道的潮流运动具有明显的定向往复流形式,潮流强,潮差大.且形成了辐射状潮流流炀;排污口排放的污染物的扩散影响范围不大,不利潮型为小湖,大潮和中潮情况下,污染面积有所减小。  相似文献   

5.
厦门浔江海域污染扩散数值模拟   总被引:1,自引:1,他引:1  
李燕初  李立 《台湾海峡》1997,16(2):174-180
本文采用ADI活动边界潮流数值模拟模拟了厦门浔江海域的潮流,计算的结果与实测数据比较吻合。文中用欧拉污染扩散数值模型计算了从同安、集美、五通口排出的污染物(COD)对浔江海域的影响,同时采用拉格朗日污染扩散数值模型研究在湾口、集美和在北部的湾顶污染物瞬时排放后的运移情况。  相似文献   

6.
本文针对大鹏湾的水环境问题,在实际调查的基础上,建立了大鹏湾水质数值模型,用计算机进行了污染物浓度场的数值模拟,并与实际资料进行了验证比较,结果表明误差较小。最后,文章结合计算结果和实测结果对大鹏湾污染物浓度场的分布和变化进行了讨论。  相似文献   

7.
宁波-舟山海域污染物扩散的数值模拟   总被引:4,自引:0,他引:4  
基于宁波-舟山海域潮流场,建立了该海域三维变边界的污染物扩散模型,对COD、无机氮、活性磷酸盐的浓度进行了数值模拟,并对界面源的影响进行了分析。结果表明:污染物浓度在海域内呈由西北向东南方向递减的趋势;COD浓度在大部分海域满足一类水质标准,无机氮和活性磷酸盐浓度在研究海域超出二类水质标准;研究海域的界面源对该海域污染物浓度”贡献”在85%以上。  相似文献   

8.
深圳湾物理自净能力研究——Ⅰ.潮流和浓度场的模拟   总被引:1,自引:0,他引:1  
张淑珍  孟伟 《海洋学报》1987,9(4):413-419
依据环境流体动力学模型和污物输运模型,利用ADI数值计算方法,数值模拟了深圳湾的潮流场和污物浓度场。计算中对边界条件的处理及湍流扩散系数的选取都作了改进,因此计算结果与实测场吻合较好。  相似文献   

9.
詹小涌 《热带海洋》1990,9(1):82-86
本针对大鹏湾的水环境问题,在实际调查的基础上,建立了大鹏湾水质数值模型,用计算机进行了污染物浓度场的数值模拟,并与实际资料进行了验证比较,结果表明误差较小。最后,章结合计算结果和实测结果对大鹏湾污染物浓度场的分布和变化进行了讨论。  相似文献   

10.
波浪增减水的实用数学模型及其数值模拟   总被引:3,自引:2,他引:3  
提出了一种模拟近岸区波浪增减水的实用数学模型.首先采用考虑波能损失的抛物型缓坡方程数值模拟波浪破碎引起的波浪复振幅变化,接着根据计算得到的波浪复振幅,采用一种新的辐射应力公式计算辐射应力分量,然后采用深度平均方程计算波浪破碎产生的增减水.采用该模型对规则波和不规则波破碎引起的增减水进行了数值模拟,数值模拟结果与实验结果吻合良好,表明该模型可有效模拟近岸区由于波浪破碎引起的增减水.  相似文献   

11.
12.
For the simulation of the three-dimensional (3D) nearshore circulation,a 3D hydrodynamic model is developed by taking into account the depth-dependent radiation stresses.Expressions for depth-depeedent radiation stresses in the Cartsian coordinates are introduced on the basis of the linear wave theory,and then vertical variations of depth-dependent radiation stresses are discussed.The 3D hydrodynamic model of EICIRC (Eulerian-Lagrangian CIRCulation) is extended by adding the terms of the depth-dependent or depth-averaged radiation stresses in the momentum equations.The wave set-up,set-down and undertow are simulated by the extended ELCIRC model based on the wave fields provided by the experiment or the REF/DIF wave model.The simulated results with the depth-dependent and depth-averaged radiation stresses both show good agreement with the experimental data for wave set-up and set-down.The undertow profiles predicted by the model with the depth-dependent radiation stresses are also consistent with the experimental results,while the model with the depth-averaged radiation stresses can not reflect the vertical distribution of undertow.  相似文献   

13.
A new form of higher order Boussinesq equations   总被引:3,自引:0,他引:3  
On the basis of the higher order Boussinesq equations derived by the author (1999), a new form of higher order Boussinesq equations is developed through replacing the depth-averaged velocity vector by a new velocity vector in the equations in order to increase the accuracy of the linear dispersion, shoaling property and nonlinear characteristics of the equations. The dispersion of the new equations is accurate to a [4/4] Pade expansion in kh. Compared to the previous higher order Boussinesq equations, the accuracy of quadratic transfer functions is improved and the shoaling property of the equations have higher accuracy from shallow water to deep water.  相似文献   

14.
Interfacial waves propagating along the interface between a three-dimensional two-fluid system with a rigid upper boundary and an uneven bottom are considered. There is a light fluid layer overlying a heavier one in the system, and a small density difference exists between the two layers. A set of higher-order Boussinesq-type equations in terms of the depth-averaged velocities accounting for stronger nonlinearity are derived. When the small parameter measuring frequency dispersion keeping up to lower-order and full nonlinearity are considered, the equations include the Choi and Camassa’s results (1999). The enhanced equations in terms of the depth-averaged velocities are obtained by applying the enhancement technique introduced by Madsen et al. (1991) and Schaffer and Madsen (1995a). It is noted that the equations derived from the present study include, as special cases, those obtained by Madsen and Schaffer (1998). By comparison with the dispersion relation of the linear Stokes waves, we found that the dispersion relation is more improved than Choi and Camassa’s (1999) results, and the applicable scope of water depth is deeper.  相似文献   

15.
A method for filtering inertia-gravity waves from elevation and depth-averaged velocity is described. This filtering scheme is derived from the linear shallow water equations for constant depth and constant Coriolis frequency. The filtered solution is obtained by retaining only the eigenvectors corresponding to the geostrophic equilibrium and by discarding explicitly the eigenvectors corresponding to the fast moving inertia-gravity waves. An alternative formulation is derived using a variational approach. Both filtering methods are tested numerically for a periodic domain with constant depth and the variational approach is implemented for a closed domain with large topographic variations. The filtering methods significantly reduce the amplitudes of the inertia-gravity waves while preserving the mean flow. The variational method is compared to the Incremental Analysis Update technique and the benefits of the variational filter are presented.  相似文献   

16.
Quasi-3D Numerical Simulation of Tidal Hydrodynamic Field   总被引:2,自引:0,他引:2  
Based on the 2D horizontal plane numerical model,a quasi-3D numerical model is establishedfor coastal regions of shallow water.The characteristics of this model are that the velocity profiles can be ob-tained at the same time when the equations of the value of difference between the horizontal current velocityand its depth-averaged velocity in the vertical direction are solved and the results obtained are consistent withthe results of the 2D model.The circulating flow in the rectangular area induced by wind is simulated and ap-plied to the tidal flow field of the radial sandbanks in the South Yellow Sea.The computational results fromthis quasi-3D model are in good agreement with analytical results and observed data.The solution of the finitedifference equations has been found to be stable,and the model is simple,effective and practical.  相似文献   

17.
《Ocean Modelling》2010,31(4):310-322
A global spectral barotropic ocean model is introduced to describe the depth-averaged flow. The equations are based on vorticity and divergence (instead of horizontal momentum); continents exert a nearly infinite drag on the fluid. The coding follows that of spectral atmospheric general circulation models using triangular truncation and implicit time integration to provide a first step for seamless coupling to spectral atmospheric global circulation models and an efficient method for filtering of ocean wave dynamics. Five experiments demonstrate the model performance: (i) Bounded by an idealized basin geometry and driven by a zonally uniform wind stress, the ocean circulation shows close similarity with Munk’s analytical solution. (ii) With a real land–sea mask the model is capable of reproducing the spin-up, location and magnitudes of depth-averaged barotropic ocean currents. (iii) The ocean wave-dynamics of equatorial waves, excited by a height perturbation at the equator, shows wave dispersion and reflection at eastern and western coastal boundaries. (iv) The model reproduces propagation times of observed surface gravity waves in the Pacific with real bathymetry. (v) Advection of tracers can be simulated reasonably by the spectral method or a semi-Langrangian transport scheme. This spectral barotropic model may serve as a first step towards an intermediate complexity spectral atmosphere–ocean model for studying atmosphere–ocean interactions in idealized setups and long term climate variability beyond millennia.  相似文献   

18.
Two sets of higher-order Boussinesq-type equations for water waves   总被引:1,自引:0,他引:1  
Z.B. Liu  Z.C. Sun 《Ocean Engineering》2005,32(11-12):1296-1310
Based on the classical Boussinesq model by Peregrine [Peregrine, D.H., 1967. Long waves on a beach. J. Fluid Mech. 27 (4), 815–827], two parameters are introduced to improve dispersion and linear shoaling characteristics. The higher order non-linear terms are added to the modified Boussinesq equations. The non-linearity of the Boussinesq model is analyzed. A parameter related to h/L0 is used to improve the quadratic transfer function in relatively deep water. Since the dispersion characteristic of the modified Boussinesq equations with two parameters is only equal to the second-order Padé expansion of the linear dispersion relation, further improvement is done by introducing a new velocity vector to replace the depth-averaged one in the modified Boussinesq equations. The dispersion characteristic of the further modified Boussinesq equations is accurate to the fourth-order Padé approximation of the linear dispersion relation. Compared to the modified Boussinesq equations, the accuracy of quadratic transfer functions is improved and the shoaling characteristic of the equations has higher accuracy from shallow water to deep water.  相似文献   

19.
A global spectral barotropic ocean model is introduced to describe the depth-averaged flow. The equations are based on vorticity and divergence (instead of horizontal momentum); continents exert a nearly infinite drag on the fluid. The coding follows that of spectral atmospheric general circulation models using triangular truncation and implicit time integration to provide a first step for seamless coupling to spectral atmospheric global circulation models and an efficient method for filtering of ocean wave dynamics. Five experiments demonstrate the model performance: (i) Bounded by an idealized basin geometry and driven by a zonally uniform wind stress, the ocean circulation shows close similarity with Munk’s analytical solution. (ii) With a real land–sea mask the model is capable of reproducing the spin-up, location and magnitudes of depth-averaged barotropic ocean currents. (iii) The ocean wave-dynamics of equatorial waves, excited by a height perturbation at the equator, shows wave dispersion and reflection at eastern and western coastal boundaries. (iv) The model reproduces propagation times of observed surface gravity waves in the Pacific with real bathymetry. (v) Advection of tracers can be simulated reasonably by the spectral method or a semi-Langrangian transport scheme. This spectral barotropic model may serve as a first step towards an intermediate complexity spectral atmosphere–ocean model for studying atmosphere–ocean interactions in idealized setups and long term climate variability beyond millennia.  相似文献   

20.
We report on the development and validation of a coupled two- and one-dimensional finite-element model for the Scheldt tributaries, river, estuary and region of fresh water influence (ROFI). The hydrodynamic equations are solved on a single, unstructured, multi-scale mesh stretching from the shelf break to the Scheldt tributaries. The tide is forced on the shelf break and propagates upstream in the riverine network. Upstream boundaries lie on sluices or outside of the region of tidal dominance where daily averaged discharges are imposed. Two-dimensional, depth-averaged shallow water equations are solved by means of the discontinuous Galerkin (DG) method over the marine and estuarine parts of the computational domain. In the rivers, however, one-dimensional equations are dealt with using the DG method with the addition of a technique to cope with confluence points. Model parameters are carefully calibrated, leading to the simulation of wind- and tide-forced flows that are in excellent agreement with available data. The diffusivity in the transport equation is calibrated using time series of salinity at various locations in the estuary. Finally, the Lagrangian residual transport in the estuary and the adjacent coastal zone is investigated. This work is a major step towards an integrated model for studying the dynamics of waterborne contaminants and the water renewal timescales in the Scheldt land-sea continuum.  相似文献   

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