北京大学学报(自然科学版)

不稳定近地面层湍流的大涡模拟

蔡旭晖,谢飞钦,陈家宜   

  1. 北京大学环境科学中心,环境模拟与污染控制国家重点实验室,北京,100871
  • 收稿日期:2001-10-08 出版日期:2002-09-20 发布日期:2002-09-20

Large-eddy Simulation for Unstable Surface Layers

CAI Xuhui,XIE Feiqin,CHEN Jiayi   

  1. Center for Environmental Sciences, State Key Lab of Environmental Simulation and Pollution Control, Peking University, Beijing, 100871
  • Received:2001-10-08 Online:2002-09-20 Published:2002-09-20

摘要: 采用加密网格的大涡模式获取边界层风、温场的高分辨率模拟结果,并据以分析近地面层大气的湍流特性。结果表明,较小的网格尺度使次网格湍流贡献率大为降低,模式计算结果对次网格参数的依赖性减小,边界层整体特征得到更好的反映。同时,模拟出的近地面层通量廓线关系及湍流速度特征与实际观测结果吻合甚好,表明模式具有反映近地面层平均运动和湍流特性的能力。

关键词: 近地面层, 大涡模拟, 湍流

Abstract: Refined grids were utilized in a large-eddy simulation(LES) model for obtaining high-resolution planetary boundary data and analyzing surface layer turbulence. Simulation results showed that refined meshes reduced turbulent contributions of subgrid scales(SGS), sensitivity of simulation results to SGS parameters decreased, and features of the whole boundary layer were explicitly resolved better. Results also revealed flux-profile relationship correctly in surface layer and a good agreement of turbulent velocity characters with observation. Therefore, it concluded that the LES method was able for simulation of surface layer flow and turbulence, and might be used for further applications.

Key words: surface layer, large-eddy simulation, turbulence

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