Analysis of sand particles’ lift-off and incident velocities in wind-blown sand flux  

作　　者：Tian-Li Bo Xiao-Jing Zheng Shao-Zhen Duan Yi-Rui Liang 

机构地区：[1]Key Laboratory of Mechanics on Western Disaster and Environment,Department of Mechanics,Lanzhou University

出　　处：《Acta Mechanica Sinica》2013年第2期158-165,共8页力学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (11072097, 11232006, 11202088, 10972164 and 11121202);the Science Foundation of Ministry of Education of China (308022);Fundamental Research Funds for the Central Universities (lzujbky-2009-k01);the Project of the Ministry of Science and Technology of China (2009CB421304)

摘　　要：In the research of windblown sand movement,the lift-off and incident velocities of saltating sand particles play a significant role in bridging the spatial and temporal scales from single sand particle＇s motion to windblown sand flux.In this paper,we achieved wind tunnel measurements of the movement of sand particles near sand bed through improving the wind tunnel experimental scheme of paticle image velocimetry（PIV） and data processing method.And then the influence of observation height on the probability distributions of lift-off and incident velocities of sand particles was analyzed.The results demonstrate that the observation height has no obvious influence on the distribution pattern of the lift-off and incident velocities of sand particles,i.e.,the probability distribution of horizontal and vertical velocities of lift-off and incident sand particles follow a Gaussian distribution and a negative exponential distribution,respectively.However,it influences the center of the Gaussian distribution,the decay constant and the amplitude of the negative exponential distribution.In the research of windblown sand movement,the lift-off and incident velocities of saltating sand particles play a significant role in bridging the spatial and temporal scales from single sand particle＇s motion to windblown sand flux.In this paper,we achieved wind tunnel measurements of the movement of sand particles near sand bed through improving the wind tunnel experimental scheme of paticle image velocimetry（PIV） and data processing method.And then the influence of observation height on the probability distributions of lift-off and incident velocities of sand particles was analyzed.The results demonstrate that the observation height has no obvious influence on the distribution pattern of the lift-off and incident velocities of sand particles,i.e.,the probability distribution of horizontal and vertical velocities of lift-off and incident sand particles follow a Gaussian distribution and a negative exponential distribution,respectively.However,it influences the center of the Gaussian distribution,the decay constant and the amplitude of the negative exponential distribution.

关 键 词：Probability distribution·Sand particles' horizontal velocities·Sand particles' vertical velocities·Center of the Gaussian distribution·Decay constant of the negative exponential distribution 

分 类 号：P931.3[天文地球—自然地理学] O35[理学—流体力学]