In this paper, the augmented version of finite volume Harten–Lax–van Leer (HLL) solver, including source terms, is extended to free-surface and pressurized mixed pipe flows over complex and frictional topography. This augmented HLL Riemann solver is employed for the flux approximation at the cell interface, where source terms are split into two parts based on the wave propagation speed. The friction term is treated using a splitting implicit method to maintain stability over dry beds. The Preissmann slot method is adopted to reproduce pressurized flow in the conduit. The performances of the numerical model are investigated by several numerical tests and compared with existing methods showing clear improvements.

在本文中，有限体积 Harten-Lax-van Leer (HLL) 求解器的增强版本，包括源项，扩展到复杂和摩擦地形上的自由表面和加压混合管流。这种增强的 HLL 黎曼求解器用于单元界面处的通量近似，其中源项根据波传播速度分为两部分。摩擦项使用分裂隐式方法处理，以保持干燥床的稳定性。采用普赖斯曼槽法再现管道内的压力流动。通过多次数值试验研究了数值模型的性能，并与现有方法进行了比较，显示出明显的改进。