基于显式有限体积法的一维河网模型

采用显式通量差分裂格式离散圣维南方程组,通过特征线方式处理边界;在局部离散中引入跨临界流熵修正和TVD限制器,以提高模型精度并保证模拟稳定性,最终构建了基于显式有限体积法的一维河网水流模型。经典算例验证表明,所建立的模型能够处理具有激波的跨临界等复杂流态;模型应用于长江南京八卦洲河段,水位和流量的验证表明该模型能够应用于实际的河网,并具有较高的精度,为显式离散方法应用于河网模型提供了一种思路。

Construction of one dimensional river network model based on explicit finite volume method

A one-dimensional river network model was constructed by discretization of Saint-Venant equations with explicit flux-ifference splitting scheme and dealing border with characteristic line method. Meanwhile, the modeling accuracy and stability are enhanced with the application of entropy correction and total variation diminishing(TVD) limiter to local discretion. In a classical numerical example, the model shows its ability in capturing complex flow conditions like trans-critical flow with shock waves. Being applied in the Baguazhou section of the Yangtze River, the model shows its performance in terms of water level and flux with higher accuracy, which is suitable for the real river network. To sum up, the model discretion introduces a new idea about explicit discretion into river network model.