共查询到19条相似文献，搜索用时 109 毫秒
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胶州湾三维变动边界的潮流数值模拟 总被引：35，自引：3，他引：35
基于Blumberg等（1986）的河口、陆架和海洋模式，引入变边界处理技术，建立了胶州湾三维变动边界的潮流模型，模型以σ-正交曲线坐标下三维非线性潮波方程为基本方程，引入2.5阶瑞封闭方程组，采用分裂算子法数值求解方程组，利用湍封闭方程求解垂直紊动粘滞系数，采用干湿网格方法模拟潮流漫滩过程，三维变动边界潮流模型计算结果与实测值吻合良好。 相似文献
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本模型以三维Navier－Stokes方程为基础,经σ-坐标变换得模式方程,然后选用特殊的插值函数,利用有限元和差分相结合的方法求解.所建模型可适应具有较为复杂岸线和海工建筑的海域潮流计算,可进行局部加密,同时能以较高分辨率揭示三维潮流的空间结构特征.本潮流模型具有省时、简便的特点. 相似文献
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建立宽浅河道与管道水流的二、三维嵌套的数学模型,对基本的控制方程、方程的数值离散格式和求解方法、嵌套连接和初始边界条件等问题进行研究.利用上述方法对某工程实例进行计算,在宽广水域上给出了水力要素的平面分布,在复杂边界强三维流动的计算区域得到其三维运动特性.计算结果与实验资料进行了比较,两者吻合较好,说明嵌套连接的二、三维数学模型是解决某些实际工程问题的一种可靠的和有效的工具. 相似文献
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以实验室二维温带风暴潮数值模型为基础,综合考虑海洋潮波动力与风应力联合作用,建立温带风暴潮三维数值计算模型.模型从推导三维风暴潮基本控制方程出发,并应用交替方向隐格式(ADI)方法对方程进行离散求解.对于浅水动边界,模型采取局部深槽、缩小水域的活动边界处理方法.利用拟三维数值计算方法,并提出了非平面水深等分模式和平面等水深分布模式,应用这两种计算模式分别对渤海湾2009年5月8～10日发生的风暴潮过程进行了数值模拟.将风暴潮位计算结果和增水位计算结果与塘沽验潮站的实际观测数值进行对比验证,结果显示受风应力与潮波联合作用的风暴潮位和增水位与实测数据吻合良好;通过比较得到了平面等水深分布模式的计算成果要比非平面水深等分模式的计算成果更接近观测资料的结论,为风暴潮预报提供了理论依据. 相似文献
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迎风有限元法在三维潮流数值模拟中的应用 总被引：4，自引：0，他引：4
为研究和开发迎风有限元法在河口海岸三维波数值模拟中的应用，并为建立三维物质扩散模型，最终为解决实际工程问题打下基础，以非线性浅水波方程为基础，采用一咱平面迎风有奶元与垂向工有限差分相结合地数值计算方法建立三维潮流数学模型，基地实际的物理过程，在计算中将三维流动分成外重力波和内重力波，耦联求解潮位和流速的空间分布。应用本模式计算了天津新港附近渤海海域的三维潮流运动，以较高的分辩率揭示了潮流空间结构特 相似文献
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给出了一些海区实测浮力频率剖面的数学模型.利用超几何函数对内波垂直模式方程进行了解析求解,得到内波模式方程的解析解和频散方程.利用得到的解析解给出了一种理想条件下内波前三阶简正模式的结构. 相似文献
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港湾三维水动力和污染物扩散数值模型 总被引：7，自引：0，他引：7
本文提出一种浅海三维污染物扩散数值模拟的方法。首先建立σ坐标系下的Navier-Stoker方程及物质扩散方程。基于过程分裂法将前者分解为外模式（二维方程组）及内模式（三维方程组）；并且引入窄缝法对变边界进行模拟，由此建立三维σ坐标潮流模型；并找到σ坐标系下三维污染物扩散方程的差分方法，最后建立三维σ坐标污染物扩散模型。本模型已被应用于厦门海域，并对其2002年海水水质（CODCr值增量)进行了预测。应用结果表明，这种三维可变边界污染物扩散数值模型能够较好地对具有较大面积浅海滩涂的海区进行水质模拟和预测。 相似文献
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MPS(Moving Particle Semi-implicit)法能够有效地处理溃坝、晃荡等自由面大变形流动问题。在三维MPS方法中,粒子数量的急剧增加会导致其计算效率的降低并限制其在大规模流动问题中的应用。基于自主开发的MPS求解器MLParticleSJTU,本文对求解过程中耗时最多的邻居粒子搜寻和泊松方程求解两个模块采用了GPU并行加速,详细探讨了CPU+GPU策略。以三维晃荡和三维溃坝这两种典型的自由面大变形流动为例,比较了CPU+GPU相对于MLParticle-SJTU串行求解时的加速情况,结果表明CPU+GPU在邻居粒子和泊松方程这两个模块中的加速比最高能达到十倍左右。此外,采用CPU+GPU并行能够较准确地模拟溃坝、晃荡等自由面大变形问题。 相似文献
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An algorithm is proposed for solving three-dimensional ocean hydrodynamics equations without hydrostatic approximation and traditional simplification of Coriolis acceleration. It is based on multicomponent splitting of the modified model with artificial compressibility. The original system of equations is split into two subsystems describing the transport of three velocity components and adjustment of the density and velocity fields. At the adjustment stage, the horizontal velocity components are represented as a sum of the depth means and deviations; the two corresponding subsystems are derived. For barotropic dynamics, the compressibility effect is represented as the boundary condition at the free surface, while for the baroclinic subsystem, it is introduced as ε-regularization of the continuity equation. Then, the baroclinic equations are split into two subsystems describing the hydrostatic and nonhydrostatic dynamics. The nonhydrostatic dynamics is computed at a separate splitting stage. The algorithm is included into the Institute of Numerical Mathematics of the Russian Academy of Sciences model based on “primitive” equations and verified by solving the hydrodynamics problem for the Sea of Marmara. 相似文献
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A three-dimensional numerical model for determination of the interaction between non-linear water waves and a structure is developed. The model is based on a boundary integral equation method for the spatial solution of a potential theory problem, combined with a time-stepping method based on the fully non-linear free surface conditions for temporal updating of moments on a structure in the fluid domain. Comparison with experimental results shows good agreement. The present model is considered to be one of the steps towards a three-dimensional numerical model in which the wave-structure interaction in a wave tank can be simulated. 相似文献
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A three-dimensional finite difference transport model appropriate for the coastal environment is developed for the solution of the three-dimensional convection-diffusion equation. A higher order upwind scheme is used for the convective terms of the convection-diffusion equation, to minimise the numerical diffusion. The validity of the numerical model is verified through five test problems, whose exact solutions are known. 相似文献
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Numerical Simulation of Spatial Lag Between Wave Breaking Point and Location of Maximum Wave-Induced Current 总被引：2，自引：0，他引：2
A quasi three-dimensional numerical model of wave-driven coastal currents with the effects of surface rollers is developed for the study of the spatial lag between the location of the maximum wave-induced current and the wave breaking point.The governing equations are derived from Navier-Stokes equations and solved by the hybrid method combining the fractional step finite different method in the horizontal plane with a Galerkin finite element method in the vertical direction.The surface rollers effects are considered through incorporating the creation and evolution of the roller area into the free surface shear stress.An energy equation facilitates the computation process which transfers the wave breaking energy dissipation to the surface roller energy.The wave driver model is a phase-averaged wave model based on the wave action balance equation.Two sets of laboratory experiments producing breaking waves that generated longshore currents on a planar beach are used to evaluate the model's performance.The present wave-driven coastal current model with the roller effect in the surface shear stress term can produce satisfactory results by increasing the wave-induced nearshore current velocity inside the surf zone and shifting the location of the maximum longshore current velocity landward. 相似文献
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Baroclinic terms have been implemented in a three-dimensional fully hydrodynamic model developed by Badiei et al. [2008. A three-dimensional non-hydrostatic boundary fitted model for free surface flows. International Journal for Numerical Methods in Fluids, 56(6), 607-627] modifying its momentum equations to account for density gradients and utilizing the scalar (salinity, temperature, etc.) conservation equation (SCE) and a state equation for the calculation of density. In the solution of advection-diffusion terms of the governing Navier-Stokes equations (NSE) and SCE, a symmetric splitting method was applied to ensure the long-term stability of simulations. Correction terms proposed by Ruddic et al. (1995) were applied to SCE to ensure the conservation of the scalar quantity. In the presence of baroclinic terms, the zero gradient pressure in the vertical direction in the vicinity of surface and bottom boundaries assumed by Badiei et al. [2008. A three-dimensional non-hydrostatic boundary fitted model for free surface flows. International Journal for Numerical Methods in Fluids, 56(6), 607-627] created spurious currents. This problem was solved by assuming a hydrostatic pressure variation at those boundaries. The ability of extended model was validated by comparing its results with an experimental test case. The simulation of hydrodynamic and salt intrusion at Anzali Port located at the southern coasts of Caspian Sea in Iran was carried out by the model with both barotropic and baroclinic modes. The simulated results with baroclinic mode show a better agreement with measured data as compared to the results of barotropic mode that clearly demonstrate the significance of baroclinic terms in the simulation of cyclic intrusion of salt wedge into the Port Basin. 相似文献
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In order to solve unsteady incompressible Navier–Stokes(N–S) equations, a new stabilized finite element method,called the viscous-splitting least square FEM, is proposed. In the model, the N–S equations are split into diffusive and convective parts in each time step. The diffusive part is discretized by the backward difference method in time and discretized by the standard Galerkin method in space. The convective part is a first-order nonlinear equation.After the linearization of the nonlinear part by Newton's method, the convective part is also discretized by the backward difference method in time and discretized by least square scheme in space. C~0-type element can be used for interpolation of the velocity and pressure in the present model. Driven cavity flow and flow past a circular cylinder are conducted to validate the present model. Numerical results agree with previous numerical results, and the model has high accuracy and can be used to simulate problems with complex geometry. 相似文献
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Settlement Analysis for An Embankment Considering Visco-Elasto-Plastic Characteristics 总被引：1，自引：0，他引：1
SHI Jianyong 《中国海洋工程》2000,14(3):349-360
—In the paper.a visco-elasto-plastic constitutive model and a method for determining modelparameters for soft clay are presented.In this model total strain of soft clay is assumed to be divided intothree parts:instantaneous elastic.visco-elastic and visco-plastic.The characteristics of instantaneous andvisco-elastic deformation of soft clay are simulated by Merchant's model.the plastic is by a model withtwo yield surfaces.And related constitutive equation is conducted,A number of stress-controlled triaxialtests are performed to calculated the model parameters The visco-elasto-plastic model is used for analysisof the displacement of an embankment on soft ground by use of three-dimensional finite element method.The predicted settlements agree well with the measured data.It is indicated that the viscous characteristicsshould be taken into account in deformation analysis for soft clay. 相似文献