Effects of the mid-air collision on sand saltation  

作　　者：HUANG Ning REN Shan ZHENG XiaoJing 

机构地区：[1]Key Laboratory of Mechanics on Western Disaster and Environment,Ministry of Education,Department of Mechanics,Lanzhou University,Lanzhou 730000,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2008年第9期1416-1426,共11页中国科学：物理学、力学、天文学（英文版）

基　　金：the Key Project of National Natural Science Foundation of China (Grant No 10532040);the National Natural Science Foundation of China (Grant Nos 40571018 and 10772073);the New Century Outstanding Talent of the Ministry of Education of China;the Science Fund of the Ministry of Education of China for PhD Program (Grant No 20060730014)

摘　　要：As to the fact that the effects of saltating particles’ mid-air collision on the sand transport rate are often neglected in the current theoretical models describing sand saltation movement,expressions to calculate velocity diversity of saltating parti-cles after mid-air collision are presented through collision theory of hard ball in this paper. Then,the theoretical model of the wind blown sand movement at the steady state,taking account of coupled interaction between saltation particles and wind,is combined with the model of the mid-air collision probability to calculate the sal-tating particles’ mass flux at heights,the sand transport rate,and further,their changing rules. The comparison of the results with those when the mid-air collision is not considered suggests that the mass flux at heights and the sand transport rate in this paper are less,and much closer,respectively,to the corresponding experi-mental values. The difference between the sand mass fluxes without and with con-sideration of mid-air collision increases at first,and then decreases as the height increases,exhibiting the stratified characteristics.As to the fact that the effects of saltating particles’ mid-air collision on the sand transport rate are often neglected in the current theoretical models describing sand saltation movement, expressions to calculate velocity diversity of saltating particles after mid-air collision are presented through collision theory of hard ball in this paper. Then, the theoretical model of the wind blown sand movement at the steady state, taking account of coupled interaction between saltation particles and wind, is combined with the model of the mid-air collision probability to calculate the saltating particles’ mass flux at heights, the sand transport rate, and further, their changing rules. The comparison of the results with those when the mid-air collision is not considered suggests that the mass flux at heights and the sand transport rate in this paper are less, and much closer, respectively, to the corresponding experimental values. The difference between the sand mass fluxes without and with consideration of mid-air collision increases at first, and then decreases as the height increases, exhibiting the stratified characteristics.

关 键 词：mid-air COLLISION SAND TRANSPORT RATE SALTATION 

分 类 号：O313.4[理学—一般力学与力学基础]