Author(s): Tetsuro Tsujimoto

Linked Author(s):

Keywords: Transport process; Aeolian sand transport; Saltation; Wind velocity; Velocity profile; Mixing length

Abstract: The motion of blown sand constitutes an interrelating system where individual particles' motion is driven by wind while it affects the turbulent structure of wind. The purpose of this study is to clarify the particle/fluid interaction, and to deduce the characteristics of blown sand and wind reasonably based on the multiphase flow mechanism. In this study, the motion of individual particles are calculated under clear wind condition (wind without blown sand), and then the turbulent structure of wind with blown sand is re-calculated. Furthermore, the motion of blown sand is recalculated under the condition of wind with blown sand. The calculation is repeated to obtain an equilibrium state of wind with blown sand. By this scenario of calculation, the turbulent structure of wind with blown sand and the characteristics of blown sand (transport rate, concentration distribution and so on) are simultaneously evaluated. For the phase of particle motion, the repulsion of a saltating particle on the bed to maintain successive saltation is important, and a simple stochastic model is employed. While, for the phase of flow, the change in profile of the Reynolds stress is a key, and velocity profile is obtained by assuming a simple mixing length model. These simplified models may have other alternatives, but such a simplification makes the particle/fluid interaction clear in this paper.

DOI:

Year: 1999