摘要
采用三维粒子示踪测速技术,通过分别变化示踪粒子的粒径、密度以及水力比降等条件,观测了6种不同水沙条件下推移质颗粒的单步运动,并对大量粒子的运动规律进行统计分析.观测结果表明,颗粒单步步长以及跳跃高度均随水流速度增大而增大,随颗粒粒径和密度增大而减小.统计规律表明,跃移颗粒单步步长的概率密度服从Γ分布,颗粒起跃段步长与总步长之比接近一个常数.
Using the 3D particle tracking velocimetry （3D PTV） technique, six runs of experiments on saltating motion of bed-load particles were performed with steady uniform flows with various particle diameters, densities and hydraulic gradients. The motion characteristics of most saltating particles were statistically analyzed. The experimental results show that the step length and height of the particles increase with the increase of flow velocity, and decrease with the increase of grain diameters and densities. The probability density distribution of step length of the sahating particles shows a Г distribution, and the ratio between the rising-phase length and the total step length is close to a constant.
出处
《河海大学学报（自然科学版）》
CAS
CSCD
北大核心
2009年第2期232-235,共4页
Journal of Hohai University(Natural Sciences)
基金
国家自然科学基金(50279013
50221903)
河海大学科技创新基金(406067)
关键词
推移质颗粒
单步运动
概率密度分布
bed load
saltating motion
probability density distribution
