Simulation of non-hydrostatic, density-stratified flow in irregular domains
Simulation of non-hydrostatic, density-stratified flow in irregular domains
复制标题
不规则域中非静水力、密度分层流的模拟
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
T. Finnigan
中科院分区：
文献类型：
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作者：
K. Winters;H. Seim;T. Finnigan
本文建立了一个模拟不规则但地形简单的区域内密度分层流的数值模型。该模型的设计是为了模拟内部重力波和地形之间的强烈相互作用，例如收缩通道中的交换流，二维底槛上的潮汐或对流驱动流或传播到浅水床上的波。该模型是基于非流体静力学，Boussinesq运动方程的连续分层流体在一个旋转的框架，受用户可配置的边界条件。采用正交边界拟合坐标系进行数值计算，采用四阶紧致微分格式、三阶显式时间推进和基于多重网格的压力投影算法。数值技术进行了描述，并提出了一套验证研究。验证研究包括数值模拟与非线性孤立波传播的解析解和实验室测量的逐点比较。缺乏分析或实验室数据的流动模拟结果进行了分析后，证明潜在的能量平衡的满意度。计算结果进行了比较与两层水力预测的情况下，交换流通过收缩通道。最后，讨论了不规则盆地中空间非均匀表面浮力通量驱动的环流模拟。
A numerical model has been developed for simulating density-stratified flow in domains with irregular but simple topography. The model was designed for simulating strong interactions between internal gravity waves and topography, e.g. exchange flows in contracting channels, tidally or convectively driven flow over two-dimensional sills or waves propagating onto a shoaling bed. The model is based on the non-hydrostatic, Boussinesq equations of motion for a continuously stratified fluid in a rotating frame, subject to user-configurable boundary conditions. An orthogonal boundary fitting co-ordinate system is used for the numerical computations, which rely on a fourth-order compact differentiation scheme, a third-order explicit time stepping and a multi-grid based pressure projection algorithm. The numerical techniques are described and a suite of validation studies are presented. The validation studies include a pointwise comparison of numerical simulations with both analytical solutions and laboratory measurements of non-linear solitary wave propagation. Simulation results for flows lacking analytical or laboratory data are analysed a posteriori to demonstrate satisfaction of the potential energy balance. Computational results are compared with two-layer hydraulic predictions in the case of exchange flow through a contracting channel. Finally, a simulation of circulation driven by spatially non-uniform surface buoyancy flux in an irregular basin is discussed.