Theoretical prediction of electric fields in wind-blown sand

Authors

  • TianLi Bo,

    1. Key Laboratory of Mechanics on Western Disaster and Environment, Lanzhou University, Lanzhou, China
    2. Department of Mechanics, Lanzhou University, Lanzhou, China
    Search for more papers by this author
  • Huan Zhang,

    1. Key Laboratory of Mechanics on Western Disaster and Environment, Lanzhou University, Lanzhou, China
    2. Department of Mechanics, Lanzhou University, Lanzhou, China
    Search for more papers by this author
  • Wei Zhu,

    1. Key Laboratory of Mechanics on Western Disaster and Environment, Lanzhou University, Lanzhou, China
    2. Department of Mechanics, Lanzhou University, Lanzhou, China
    Search for more papers by this author
  • XiaoJing Zheng

    Corresponding author
    1. Key Laboratory of Mechanics on Western Disaster and Environment, Lanzhou University, Lanzhou, China
    2. Department of Mechanics, Lanzhou University, Lanzhou, China
    • Corresponding author: X. Zheng, Department of Mechanics, Lanzhou University, Lanzhou, 730000, China. (xjzheng@lzu.edu.cn)

    Search for more papers by this author

Abstract

[1] Existing experimental and theoretical studies have identified the existence of an electric field in wind-blown sand, whose strength is hundreds to thousands of times larger than that of the fair-weather electric field (around 120v m− 1) and is related to the intensity of the wind-blown sand transport. The direction of electric field is often upward pointing and opposite to that of the fair-weather electric field. In this study, we performed theoretical predictions of electric fields in wind-blown sand transport by assuming a constant charge-to-mass ratio (i.e., − 60µc kg− 1) of the saltating particles and considering the streamwise spatial variation of particle concentration in the evolution of wind-blown sand. Our results show that there exist both vertical and horizontal electric fields in wind-blown sand transport. The numerical results of vertical electric fields and mass flux are in good agreement with the experimental data measured by Schmidt et al. [1998] and Shao and Raupach [1992], respectively, which suggests that our model is valid. The horizontal electric field demonstrates a vertical stratification feature and is about one order of magnitude bigger than the fair-weather electric field. Finally, the effects of the wind speed and the sand grain diameter on electric fields are discussed.

Ancillary