沙粒跃移轨迹参数的统计研究

Statistic Study on Trajectory Parameters of Saltating Sand Grains

高速频闪摄影从实验技术上加强了对沙粒跃移运动及其参数的研究,但因拍摄沙粒的成像点不完整又存在局限性,用曲线拟合高速频闪摄影的跃移沙粒轨迹可以补足缺失的成像点。本文对高速摄影的沙粒轨迹进行曲线拟合,从拟合曲线反求出沙粒的起跳角θ0、上升段跃高H1、上升段跃距L1、沉降角θt、下降段跃高H2、下降段跃距L2,并对各参数进行统计分析,得出各参数间的函数关系式,为进一步研究颗粒跃移运动过程提供基础。

The study for the movement and the related parameters of saltating sand grains is strengthened by the high-speed photography technique. But it has limitation due to the imperfection of image-forming point. The defect can be covered by fitting the trajectory path of saltating sand grains with smooth curve. The trajectory of the saltating sand grain taken by the high-speed photography is analyzed with fitting curve method in this paper. The parameters launch angle θ\-0,maximum height H_(1) and maximum path length L_(1) of ascending trajectory path, collision angle θ\-t, maximum height H_(2) and maximum path length L_(2) of descending trajectory path are counted out from the fitting curve equation. Statistic analysis is used for all the parameters. The result of functions is yielded in by this way and it supplies further studies on the course of motion of saltating grains.