水平旋转内消能泄水道空腔环流的旋流特性

Swirl characteristic of level hollow swirling flow in inner dissipation discharge tunnel

本文通过对典型的竖井进流水平旋转内消能泄水道空腔环流的试验观测 ,在流速分布的假定下 ,提出与建立了该体型泄水道各种旋流特性的表达式 ,并给出试验观测结果。试验观测结果表明 ,相对于起始断面的各种旋流特性具有明显的分段性质和沿程衰减的特性 ;下游水位对空腔环流的旋流特性有显著的影响。通过理论分析定义的无量纲综合性无因次旋流参数AM ,物理意义明显 ,较全面的反映了各种基本物理量对空腔环流的影响 ,其沿程线性增大 ,表明空腔环流的断面总动量矩的沿程变化率与单位长度上的壁面切应力对轴心的力矩成正比。

In this paper,mathematical expressions of some swirl characteristics of typical level hollow swirling flow in inner dissipation discharge tunnel with inlet shaft have been put forward under velocity distribution supposition.Experiment results show that these swirl characteristics compared to their first section's values have the obvious properties of zoned change and unrestricted attenuation along tunnel length,and are obviously influenced by down water level of the tunnel.A synthetic and dimensionless swirl characteristic parameter A -M is defined according to theoretical analysis,which indicates the influences of various essential physical variables of the swirling flow,has specific physical meaning and increases linearly along the tunnel length,and shows that the ratio of section-average total moment of momentum to the moment of tunnel wall shear stress per unit tunnel length is linear.