地理科学 ›› 2015, Vol. 35 ›› Issue (5): 652-657.doi: 10.13249/j.cnki.sgs.2015.05.652

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横向沙丘表面气流湍流特征野外观测

张正偲(), 董治宝   

  1. 中国科学院寒区旱区环境与工程研究所 中国科学院沙漠与沙漠化重点实验室, 甘肃 兰州 730000
  • 收稿日期:2014-01-07 修回日期:2014-03-01 出版日期:2015-05-20 发布日期:2015-05-20
  • 作者简介:

    作者简介:张正偲(1979-),男,甘肃靖远人,副研究员,博士,主要从事风沙物理和风沙地貌研究。E-mail:zhangzhsi@sina.com

  • 基金资助:
    国家自然科学基金项目(41101007)、国家重大科学研究计划(2013CB956000)、中国科学院西部之光项目、国家国际科技合作专项项目(2011DFA11780)资助

Field Observation on the Flow Turbulence Characteristics Over Transverse Dune

Zheng-cai ZHANG(), Zhi-bao DONG   

  1. Key Laboratory of Desert and Desertification, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China
  • Received:2014-01-07 Revised:2014-03-01 Online:2015-05-20 Published:2015-05-20

摘要:

沙丘形态动力学特征是风沙地貌的重要研究内容之一,受观测技术等的限制,现有的关于沙丘形态动力学特征的研究成果还不能满足沙丘形成与演化过程研究的需要。利用三维超声风速仪对腾格里沙漠的横向沙丘表面气流特征进行野外观测,结果表明,沙丘脊线和迎风坡中部的气流均为未偏向流,而沙丘背风坡不同高度的气流包括反向流,偏向流和未偏向流。湍流强度、雷诺应力和气流丰富度随气流方向变化而变化,其在沙丘脊线和中部的变化趋势比较简单且有大致相似的规律,而其在沙丘背风坡不同高度比较复杂。

关键词: 反向流, 湍流强度, 雷诺应力, 气流丰富度

Abstract:

Dune morphology dynamic is one of the main issues in aeolian geomorphology research. Because of the restriction of measurement technology, the research result on the aeolian geomorphology dynamic is unable to meet the need for dune formation and development at present. Sonic anemometer could measure the high frequency three direction wind velocity simultaneously, and could provide detailed flow information over dune surface. The results indicated that the flow structure at dune ridges and middle part is deflected; however, the flow structure at dune toe is reversal, deflected and undeflected. The flow direction at the ridge is asymmetric for the formation of reversal and deflected flow at the toe. Turbulence intensity, Reynolds stress and flow exuberance changed with flow direction, and has the similar rule at the dune ridge and middle part over dune surface, but it’s complicated at dune toe.

Key words: reversal flow, turbulence intensity, Reynolds stress, flow exuberance

中图分类号: 

  • P931.3