复杂条件下地表颗粒物运动的力学机制研究

By using the methods of wind-tunnel measurement and numerical simulation, to study and summarize the effects from the surface factors (i.e. terrain, vegetation and the texture of soil) and wind turbulence to the motion of the surface particles (represented by sand, snow and dust); The project proposes to expose and improve the dynamical mechanism for surface particles in complex situation, based on the analysis of the relationship between the factors mentioned above and the particle movement. The work tries to establish and improve parameterizations with explicit physical meaning for the surface and wind field condition, to provide the quantitative relationship between the situation factors and the particle flow, to find the characteristic and the similarity between different kinds of particles, and also the interactions between the moving particles. Finally, we try to establish a uniform aerodynamic model for the motion of surface particles in the surface layer, which can provide an effective supporting for engineering application.

采用风洞实验和数值模拟相结合的方法，研究和总结地形起伏、植被覆盖、土壤成分等地表随机因素以及近地层湍流特征对近地层颗粒物质（以沙粒、雪粒和粉尘为代表）运动规律的影响；从机理上分析和建立上述因素与近地层颗粒物质运动的物理关联，进一步弄清复杂条件下地表颗粒物质运动的动力学机制。建立健全针对地表条件及风场特征的具有明确物理意义的参数化描述；给出颗粒流运动与各环境参数的定量关系；找出不同类型颗粒在近地层运动中的特性和共性及其在运动过程中的相互影响，建立统一的近地层颗粒物质运动的动力学模式，为工程实际应用提供技术支持。

本项目采用了风洞实验、理论分析和数值模拟相结合的方法，重点研究了：多种地表粉尘释放的规律和特点；湍流风场作用下地表剪切力的分布特征及其对颗粒起动的影响；障碍物周围的空气流动特点和颗粒物输运和沉积规律；真实沙粒的粒床击溅过程以及颗粒地表波纹形态的形成机理分析等多个问题。通过对这些问题的深入研究，积累了大量的实验数据并总结出合理的规律，进一步厘清了近地层颗粒运动的一般规律及其与湍流、地表形态等环境因素之间的定量关联，针对其中一些微观物理过程给出了更为清晰的物理解释和参数描述，这些工作为我们更加深刻的认识近地层颗粒运动的本质特征，指导相关的工程应用工作提供了坚实的理论基础和技术支持。