中国物理B ›› 2007, Vol. 16 ›› Issue (7): 2033-2039.doi: 10.1088/1009-1963/16/7/038

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New expressions for the surface roughness length and displacement height in the atmospheric boundary layer

李惠君1, 张凯1, 林建忠2   

  1. (1)State Key Laboratory of Fluid Power Transmission and Control, Zhejiang University, Hangzhou 310027, China; (2)State Key Laboratory of Fluid Power Transmission and Control, Zhejiang University, Hangzhou 310027, China;China Jiliang University, Hangzhou 310018, China
  • 收稿日期:2006-10-07 修回日期:2007-01-18 出版日期:2007-07-20 发布日期:2007-07-04
  • 基金资助:
    Project supported by the Major Program of the National Natural Science Foundation of China (Grant No 10632070).

New expressions for the surface roughness length and displacement height in the atmospheric boundary layer

Lin Jian-Zhong(林建忠)a)b)†, Li Hui-Jun(李惠君)a), and Zhang Kai(张凯)a)   

  1. a State Key Laboratory of Fluid Power Transmission and Control, Zhejiang University, Hangzhou 310027, China; b China Jiliang University, Hangzhou 310018, China
  • Received:2006-10-07 Revised:2007-01-18 Online:2007-07-20 Published:2007-07-04
  • Supported by:
    Project supported by the Major Program of the National Natural Science Foundation of China (Grant No 10632070).

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摘要： An alternative model for the prediction of surface roughness length is developed. In the model a new factor is introduced to compensate for the effects of wake diffusion and interactions between the wake and roughness obstacles. The experiments are carried out by the use of the hot wire anemometry in the simulated atmospheric boundary layer in a wind tunnel. Based on the experimental data, a new expression for the zero-plane displacement height is proposed for the square arrays of roughness elements, which highlights the influence of free-stream speed on the roughness length. It appears that the displacement height increases with the wind speed while the surface roughness length decreases with Reynolds number increasing. It is shown that the calculation results based on the new expressions are in reasonable agreement with the experimental data.

关键词: roughness length, zero-plane displacement height, atmospheric boundary layer, free stream speed, packing density

Abstract: An alternative model for the prediction of surface roughness length is developed. In the model a new factor is introduced to compensate for the effects of wake diffusion and interactions between the wake and roughness obstacles. The experiments are carried out by the use of the hot wire anemometry in the simulated atmospheric boundary layer in a wind tunnel. Based on the experimental data, a new expression for the zero-plane displacement height is proposed for the square arrays of roughness elements, which highlights the influence of free-stream speed on the roughness length. It appears that the displacement height increases with the wind speed while the surface roughness length decreases with Reynolds number increasing. It is shown that the calculation results based on the new expressions are in reasonable agreement with the experimental data.

Key words: roughness length, zero-plane displacement height, atmospheric boundary layer, free stream speed, packing density

中图分类号:  (Boundary layer turbulence ?)

  • 47.27.nb
47.27.Jv (High-Reynolds-number turbulence)