推移质颗粒跃移运动的随机特性

Stochastic Feature of Parameters of Particle Saltation

推移质颗粒跃移特性具有两重性,既有确定性的一面,也有随机性的一面.作者为了研究推移质跃移机理,曾应用高速摄影技术,系统地测量了推移质颗粒的跃移过程.本文重点分析了跃移运动的随机性,利用统计分析的方法对跃移颗粒的跃长、跃高、跃移速度,起跃和落地速度等运动参数进行了分析,结果表明:跃高和跃长的概率密度服从分布,跃移速度、起跃和落地速度的概率密度服从正态分布,试验资料与运动参数的理论分布取得了较好的一致性,文中对跃移各运动参数的数值特性也进行了分析.这方面的研究对于泥沙运动机理的深入了解及工程实际有着重要的意义.

Particle saltation has both definite respect and stochastic respect. The trajectories of numbers of particles with different specific gravity are measured by high speed photographic technology in this study, and sto-chastic feature of particle saltation is analysed by the method of statistical analysis. It is concluded that the probability density distributions of relative saltation height and length submit to r-distribution. The relative saltation velocity, lift-up velocity and fall velocity submit to Gauss-distribution. The measured data agree with these distribution very well. The characteristic value of statistics of parameter of particle saltation is analysed also.