SCIENTIA GEOGRAPHICA SINICA ›› 1999, Vol. 19 ›› Issue (5): 475-478.doi: 10.13249/j.cnki.sgs.1999.05.475

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Mechanical Analysis of a Single Saltating Particle in Air Flow

YANG Bao, ZOU Xue-yong, WANG Zhou-long, DONG Guang-rong, LIU Yu-zhang   

  1. Lanzhou Institute of Desert Research, Chinese Academy of Sciences, Lanzhou Gansu 730000
  • Received:1998-05-26 Revised:1999-03-28 Online:1999-09-20 Published:1999-09-20

Abstract: Mechanical analysis of a single saltating particle in air flow and its motion mechanism play an important role in development the Physics of Wind blown Sand. By means of high speed multi flash photography, this paper analyzes the variation law of drag coefficient and lift coefficient of saltation particle, and makes a comparison between drag, lift force and gravity force. Conclusions are as follows. First, drag coefficient of sand particle is different from one of idealistic small sphere. Second, among all forces, drag whose values can reach several times of gravity force is the most important, gravity force lists second, and lift force which accounts for more than 20% is not negligible. Third, using numerical method, saltating trajectory of sand particle has been obtained. Comparison of computed trajectory and measured trajectory shows that mechanical analysis discussed forward is very reasonable. Last but not least, sand particle may be subject to other forces similar to Magnus or Saffman lift forces.

CLC Number: 

  • P401