基于混合数值解法的一维全水动力学畦灌模型

One-dimensional complete hydrodynamic model for border irrigation based on hybrid numerical method

数值模拟畦(沟)灌水流运动过程可为地面灌溉系统设计与评价提供必要的工具和手段。该文采用时-空混合数值解法构建起一维全水动力学畦灌模型,并基于典型畦灌试验结果,对比分析采用混合数值解法和Roe有限体积法数值求解一维畦灌全水动力学模型在数值计算稳定性与收敛性、计算精度与效率间的差异,验证基于混合数值解法的模型模拟效果。结果表明,混合数值解法要比Roe有限体积法表现出更佳的数值计算稳定性和收敛性,形成的水平衡误差和平均相对误差相对较低,相同度量环境下的计算效率提高2倍以上。基于混合数值解法的一维畦灌全水动力学数值模拟方法可明显增强数值计算的稳定性和收敛性,有效提高了计算精度和效率,为开展畦灌系统设计与性能评价提供了可靠的数值模拟手段。

Numerical model of border or furrow irrigation flow movement is a necessary tool and approach to design and evaluate surface irrigation systems.A one-dimensional complete hydrodynamic model for border irrigation was established by time-space hybrid numerical method.Then the differences of stability and convergence,the precision and efficiency of one-dimensional complete hydrodynamic model of border irrigation were compared and analyzed between the hybrid numerical method and the Roe finite volume method. At the same time, the computational performance and simulation effect were validated based on the simulation results of typical border irrigation tests. The results show that the hybrid numerical method puts up better numerical stability and convergence, and little water quality balance error and average relative error than the Roe finite volume method, and the former computational efficiency is about three times as much as the in the same measurement circumstances. The one-dimensional complete hydrodynamic model for border irrigation based on the hybrid numerical method can obviously increase computational stability and convergence, and effectively improve computational precision and efficiency, and provide a good numerical simulation tool for the design of border irrigation system and performance evaluation.