本文应用流体计算软件FLUENT6.3，采用非结构化网格划分技术模拟了气流特征和砾石几何参数对床面空气动力学粗糙度的影响。结果表明：空气动力学粗糙度（z0）与风速（u）、摩阻速度（u*）之间存在定量关系：z0=a exp（bu/u*）。砾石高度对空气动力学粗糙度的影响显著优于砾石直径，空气动力学粗糙度随砾石密度的变化比较复杂，先增加后减小。FLUENT在模拟风洞砾石床面动力学过程中的成功应用，是我们在研究方法上的一次有益尝试。
In this paper, using FLUENT6.3 we simulate effect of wind flow and gravels' geometric parameters on aerodynamic roughness length. The results indicate that aerodynamic roughness is a function of wind flow, and the variation of aerodynamic roughness (z0) with wind speed (u), friction velocity (u*) can be expressed by an exponential fuction: z0=aexp(bu/u*). Gravel height has more significant influence on aerodynamic roughness length than gravel sizes; the aerodynamic roughness increases firstly with gravel density, then decreases. The successful application of FLUENT6.3 in simulation of aerodynamic process of gravel beds is a beneficial attempt.
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