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中国沙漠 ›› 2011, Vol. 31 ›› Issue (3): 632-638.

• 国家重点基础研究发展规划 • 上一篇    下一篇

流场中集沙仪集沙效率的数值模拟

安 磊, 黄 宁*   

  1. 兰州大学 西部灾害与环境力学教育部重点实验室, 甘肃 兰州 730000
  • 收稿日期:2010-12-12 修回日期:2011-01-27 出版日期:2011-05-20 发布日期:2011-05-20

Numerical Simulation of Sampling Efficiency in a Sand Trap

AN Lei, HUANG Ning   

  1. Key Laboratory of Ministry of Education for Mechanics on Western Disaster and Environment, Lanzhou University, Lanzhou 730000, China
  • Received:2010-12-12 Revised:2011-01-27 Online:2011-05-20 Published:2011-05-20

摘要: 以管状集沙仪为例,数值模拟了它在风沙流结构中的流动特征以及集沙效率。为了使模拟更加符合真实情况,对计算区域的网格进行加密,计算了集沙仪周围的风场,并分析了网格划分对计算结果的影响。通过分析计算结果,讨论了不同薄膜渗透率对集沙仪周围风场流动特征的影响,以及不同渗透率下不同粒径沙粒的轨迹以及集沙效率。在模拟集沙效率时发现集沙仪薄膜的渗透率是影响集沙效率的一个重要参数,通过分析结果,发现选择集沙仪薄膜的时候应选择渗透率,这样随着沙粒粒径的变化,集沙效率变化趋于稳定。有两个影响集沙效率的重要因素:粒径和集沙仪进口处的流线。当颗粒粒径相对较大的时候,惯性起主要作用,对于粒径大于200 μm的沙粒来说,集沙效率几乎都在90%;当颗粒粒径相对较小的时候,流线起主要作用。

关键词: 集沙仪, 集沙效率, 数值模拟

Abstract: This paper makes a numerical simulation of the flowing characteristics and sampling efficiency of the Tubular Sand Trap for example in the sand flow structure. In order to make the simulation more truthful, we make the gridding better against the calculation domain, calculate wind field around sand trap, and analyze the effect of the gridding division to the calculation results. Through the analysis of the calculation results, we discuss the influence of different membrane permeabilities to wind field flowing and the calculation of the traces of different grain-sized particles as well as sand catcher efficiencies in the condition of different permeabilities. Based on simulation of sampling efficiency, we find that membrane permeabilities of sand trap is a vital factor of influence sampling efficiency, and through the analysis of the results, we find that choosing sand trap membrane we should choose permeability, for sampling efficiency tend to be steady with alteration of particles grain sizes. There are two key influence factors of sampling efficiency: the grain size and the streamline on the entrance of the sand catcher. When the grain sizes are comparatively big, it will be the inertia that plays the leading role, and the sampling efficiency are almost above 90% as for most of the particles with their average size of grains being 200 μm; when they are comparatively small, the streamline will be pivotal.

Key words: sand trap, sampling efficiency, numerical simulation

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