推移质颗粒3维运动紊动特性试验研究

Experimental Study on the 3D Motion Turbulence Characteristics of Bed-load Particles

采用3维粒子示踪测速技术,观测了10种不同示踪粒子的粒径、比重以及水力比降等水沙条件下推移质颗粒的3维运动,并对其紊动特性进行了统计分析。分别探讨了粒径、比重及水力比降对推移质颗粒紊动强度的影响,定性总结了3个方向上紊动特性的变化规律。实验结果表明,推移质颗粒的纵向紊动强度随粒径减小和水力比降的增大而加大,垂向和横向紊动强度在近壁区的变化规律与纵向相反,颗粒比重对紊动强度的影响不明显。

In steady uniform flows with different particle diameter,specific gravity and flow slope,ten runs of experiments with bed-load particles were performed using a three dimensional particle tracking velocimetry（3D PTV） technique,and then the turbulence velocity characteristics of bed-load particles were analyzed statistically.The experimental results showed that the longitudinal turbulence intensity of bed-load particles increases with the decrease of diameter and the increase in slope.In the near wall region,the vertical and transverse turbulence intensities showed the reverse law with the longitudinal.The specific gravity has inconspicuous effect on the turbulence intensities.