河口分层流的三维数值模拟

Three-dimensional numerical model for stratified flow in tidal estuaries

作者在周思平的博士论文——HH-SIMPLE方法的基础上,对其补充方程二的离散格式,作了进一步改进,使得改进后的HH-SIMPLE计算模式可适用于一般的潮汐河口的往复流动和更复杂的三维含自由水面的流动,从而扩充了该模式的应用范围.本文针对长江口北槽情况,采用k-ε紊流模型来闭合三维非恒定雷诺方程,建立三维数学模型,运用上述改进后的计算模式进行了数值计算,通过实测资料的验证,表明该数学模型及计算方法较好模拟了北槽潮汐流动的水动力结构和盐淡水混合的特征.在此基础上,分析探讨了北槽流速、含盐度的分布特征.

Some modifications have been made on the HH-SIMPLE method proposed by Zhou Siping in his doctoral thesis.The improved method can be applied to three dimensional and complicated flows in tidal estuaries with free surface,thus enlarges its range of application.In its application in.the North channel of Yangtse Estuary,numerical analysis is used to solve three dimensional unsteady Reynolds equations based on K-s turbulence model.The calculated results of stratified flow agree well with those of observation.It is shown that this mathematical model and computation method are able to simulate the hydrodynamic characteristics of flow and mixing features of fresh and salt water in the North channel.Finally,the distributions of flow velocity and salinity in the same channel are discussed.