河道三维错层的水流泥沙数学模型

应用垂向坐标变换，结合水平有限元、垂向有限差分的分层方法建立了河道拟三维水流泥沙数学模型．对过流断面变化剧烈的河段提出了错层计算方法，弥补了同层网格垂向落差较大的分层模型缺陷．利用水流泥沙理论解对模型计算结果进行了验证．采用该模型对海河下游河段穿河隧道施工过程中主体隧道悬浮于主流区时的水流泥沙情况进行了数值模拟，流速模拟结果与半理论半经验公式估算结果基本一致，为明渠流和河道中悬浮建筑物下压力流的混合计算提供了一种新的计算方法，拓展了三维分层水流泥沙数学模型的应用空间．

Mathematical Modeling of Flow and Sediment in Interlace Layers Riverway

The mimetic 3D mathematical model of flow and sediment in riverway was set up applying vertical coordinate transformation method, horizontal finite element method and the vertical finite difference method. The interlace layers calculation method was put forward to be used in the changing violently section to remedy the flaw of the delamination model which falls larger in vertical between the same layer grids. The calculation results were validated using the flow and sediment theoretical results. In the process of traversable gallery construction of Haihe river lower reach, the flow and sediment movement was simulated when the main body of tunnel is suspending on the main flow section, and the flow velocity simulation results accorded well with the calculation results. The results provide a new calculation method for the open channel flow and the pressure flow of the underwater suspending buildings, which extends the application space of the 3D delamination of flow and sediment mathematical model.