复杂流场的二维数值模拟方法

提出了基于二维数学模型对溢洪道下游三维复杂运动流场进行模拟计算的一种新方法.通过对泄洪建筑物下游河道复杂流场水流运动及河床冲刷状况的分析,研究了自由面流消能区水流扩散方式、流动特征及相关水力要素的概化确定.根据主流下回流区和表层水股之间质量交换很小的特点,提出了把底部回流区域作为河道无实际过流部分,即修正河流下边界条件,对溢洪道挑坎下游复杂流场进行二维数值模拟的方法.利用上述方法对某工程实例进行了数值模拟计算,计算结果与实际流场状况比较一致,较为真实地反映了自由面流区的流动.

2-D numerical method for simulating complex flow field

A new method based on 2-D mathematical model was proposed to simulate complex 3-D flow field downstream of a spillway. The flow characteristics and hydraulic factor's generalization of free-surface flow were studied by analyzing water movement and diffusion pattern, and the bed scouring of the complex flow field downstream of discharge structure. Due to little mass exchange between the mainstream of free-surface flow and bottom circumfluence, it was reasonable to conclude the flow in the bottom circumfluence has no influence on discharge so that the water interface between the mainstream of free-surface flow and bottom circumfluence area can be treated as the boundary condition in 2-D numerical simulation of flow field downstream of a spillway. This method was applied to a practical case, where the obtained results accorded well with the actual flow field.