本文基于激光衍射技术提出了一种新的浓度测量的改进方法。该方法可以同时获得测量颗粒的浓度和粒径分布。基于这一测量方法,通过对大型风洞风沙两相流系统中不同风速,高度条件下颗粒浓度和粒径测量,获得了跃移颗粒的空间结构信息。结果显示,颗粒浓度随来流风速线性增加,且在近床面区域内来流风速对颗粒粒径具有选择性。
Based on laser-diffraction technique, the improved method of particle concentration measurement is proposed in this paper. The information of particle size and concentration can be obtained simultaneously by this method. Based on this method, detailed data about the distribution of the particle size and concentration in aeolian-sand flows near sand-bed surface are obtained in a large-scale sand-bed wind tunnel experimental system. The experimental result shows that particle number concentration increases linearly with the increase of the wind velocity, and the free-stream wind velocity close to the mobile bed has selectivity for particle size.