感潮河网水流不仅受径流、潮汐动力的双重影响,还常受水闸调度等人类活动的影响,水动力条件极为复杂。针对水闸调度影响下感潮河网复杂水动力及其伴随物质输移扩散模拟,提出了考虑水闸调度并集成输运对流项的水流-输运通量耦合求解器,建立了基于非结构网格Godunov格式的二维水流-输运耦合数学模型。采用具有时空二阶精度的MUSCL—Hancock预测-校正格式,结合变量重构限制器技术,在保证计算精度的同时避免了数值振荡。运用斜底三角单元网格表达水闸线状地形,并通过地形调整模拟了水闸启闭过程。算例研究表明,该模型计算精度高,可有效模拟水闸调度影响下感潮河网水流运动及污染物输运过程,具有较好的推广应用价值。
Water flows in tidal river network are governed by channel runoff, tidal power and potential sluices operations, so the corresponding hydrodynamic conditions are very complex. To simulate the flow-mass transport in tidal river network under sluices operations, an integrated solver is proposed for computing flow and mass transport fluxes simultaneously, and then a two-dimensional coupled flow-mass transport model based on unstructured Godunov-type scheme is developed. The MUSCL-Hancock predictor-corrector scheme combined with the slope limiter is adopted to achieve the high-accuracy and high-resolution property. The sloping bottom grid is used to represent the sluice as a linear topography, and the sluice operation is modeled through adjusting the nodal bed elevation. Numerical results of test examples and field application show that the model is accurate, and can efficiently simulate complex flow and mass transport in tidal river network under sluices operations, thus has bright application prospects.