模拟风沙运动的离散颗粒动力学模型

Discrete Particle Dynamics Model for Simulating Sediment Transport by Wind

根据风沙运动的特点 ,建立了基于单沙粒动力学的离散颗粒动力学模型。依据该模型 ,模拟了 90 0 0个沙粒在风力作用下由静止不动到充分发展的稳定态的全过程 ,细致研究了沙床处于稳定态时床面形态、跃移轨迹以及跃移质 蠕移质间交换规律 ,所得结果有助于理解风沙运动的内部机理 ,这是目前常用的模型所做不到的。研究表明 :离散颗粒动力学模型能够真实的模拟风沙运动现象 ,研究范围涉及风沙运动规律和床面形态的发生与发展等关键的问题 ,因而比其它模型更具优势。

A discrete particle dynamics model of two dimensional sand transport by wind has been developed in which the motion of grain is considering individual particle motions while wind velocity distribution is given according to experimental observations. The above model has been used for simulating the phenomenon of 9000 grains movement, resulting in ripples, saltation paths above surface, which are all in good agreement with the known experimental results. Exchange between saltation and surface creep along surface is also measured, which is helpful for revealing the intrinsic mechanism of sand movement, but very hard to the commonly used methods and regular experimental measurements. Therefore, the discrete particle dynamics model can authentically simulate sand movement and offer more detailed information, which could be applied in a wider suitable range in comparison with previous the commonly used models.