风沙流中气固两相速度场的PIV-PLIF测量  

Simultaneous Velocity Measurements of Gas-Solid Phases in Eolian Sediment Transport by Particle Image Velocimetry-Planar Laser Induced Fluorescence

作　　者：杨斌[1] 王元[1] 张洋[1] 

机构地区：[1]西安交通大学能源与动力工程学院,西安710049

出　　处：《西安交通大学学报》2009年第7期101-104,共4页Journal of Xi'an Jiaotong University

基　　金：国家科技攻关"十五"计划专项经费资助项目(2004BA901A21);新疆维吾尔自治区"十五"攻关重大项目(200833121)

摘　　要：结合粒子图像测速技术与平面激光诱导荧光法,对风沙流中气固两相的速度场同时进行了测量.实验采用罗丹明B溶液作荧光剂,通过超声雾化方式产生平均直径为2μm的气相荧光示踪粒子.使用两组滤镜分别过滤荧光(橙色)与激光(绿色),通过两个CCD相机分别获得气固两相示踪粒子图像对.采用互相关算法及相应的图像处理方法进行后处理,从而获得两相的速度场.结果显示:风沙流两相的速度廓线在上部均满足对数分布;随着高度的降低,在床面附近风速梯度单调递减,风速廓线下凹,而沙粒与风场不断交换动量,相应地沙粒相速度廓线也会出现向下的偏离;6组沙样的速度廓线发生偏离的高度基本一致;沙粒粒径不仅影响沙粒本身的运动速度,同时对气相风场也有一定的影响.In this study, a new method was presented to determine simultaneously the velocity fields of gas-solid phases in the eolian sediment transport by means of PIV and PLIF. The fluorescent seed particles were micro particles atomized from rhodamine B solution. The specific optical filters and the two CCD cameras were employed in the measurement. The cross correlation algorithm and the corresponding image processing technology were used in the processing of the resulting vector plots. The samples at the south edge of Taklimakan Desert were measured. The velocity fields of the two phases were obtained. The results show that the horizontal velocities of the both phases had approximate logarithm distributions in vertical direction at the upper part of the inferior boundary layer of airflow. With the decrease of height, the gradient of the wind speed near the bed surface decreased monotonically and there was a pit in each velocity profile curve of both phases. The deviations occurred at approximately uniform height for all samples. In addition, the horizontal velocities of both phases would change with the sand grain size.

关 键 词：风沙流 粒子图像测速技术 激光诱导荧光法 荧光示踪粒子 粒径 风速廓线 

分 类 号：O359[理学—流体力学] X169[理学—力学]