基于流速幂级数解的明渠纵向离散系数计算方法

摘要

针对纵向离散系数计算多直接采用经验公式或在流速分布的求解中引入经验公式,不能完全反映离散物理机制的问题,基于矩形断面一维水流控制方程,利用幂级数求解流速分布的理论解,提出了矩形断面明渠纵向离散系数的计算方法,并进一步将其推广至天然河流.利用该方法计算了104条天然河流的纵向离散系数,结果表明计算值与实测值处于同一量级,计算结果在可接受范围内.%The longitudinal dispersion coefficient is usually computed directlyby empirical formulas or indirectly through introducing empirical formulas during the solution tovelocity distributions,which cannot fully reflect the physical mechanisms of dispersion.Based on the one-dimensional governing equation of river dynamics,a method to calculate longitudinal dispersion coefficient involving a power series solution to velocity distributionwas proposed.This formulation has been extended to the applications in 104 natural rivers with simplified rectanglecross-sections.The computed values are in the same order of magnitudes with the measured ones,indicating acceptable results.