沙粒级配对沙波纹形态影响的风洞实验研究  

Wind tunnel research into the effect of particle size distribution on sand ripple morphology

作　　者：梁依茹 吕萍 曹敏 马芳 夏子书 余军林 吴婧妍 Liang Yiru;Lv Ping;Cao Min;Ma Fang;Xia Zishu;Yu Junlin;Wu Jingyan(School of Geography and Tourism,Shaanxi Normal University,Xi'an 710119,China)

机构地区：[1]陕西师范大学地理科学与旅游学院,陕西西安710119

出　　处：《中国沙漠》2025年第1期20-31,共12页Journal of Desert Research

基　　金：国家自然科学基金项目(42271006);中央高校基本科研业务费专项项目(GK202202004)。

摘　　要：风成沙波纹是风在沙质地表塑造的呈波状起伏的微地貌,其形态特征主要受风速和粒径的影响,然而很少有研究关注沙粒级配的作用,因此对于影响沙波纹形态因素的认知并不全面,数值模拟等研究方法的发展大大受限。基于风洞实验,设置了9组粒度配比下的沙波纹形态观测,并利用Matlab软件提取特征参数,再对沙波纹的发育过程、饱和形态进行了分析,期待对以往研究予以补充,并提供实验数据与对比参考。结果表明:(1)沙床颗粒中存在30%以上的相对细沙,可以有效促进沙波纹的形成;相对粗沙的存在,使得沙波纹波长和沙波纹指数的上限增大。(2)沙粒级配因素的介入,影响了沙波纹发育过程的复杂程度,使得到达稳定饱和阶段的时间并不随着风速的增加而线性减小。(3)当风速增加时,双粒径和三粒径混合沙形成的沙波纹形态的复杂性和不均匀性更加显著;细沙∶粗沙=1∶1的粒度配比可以更快地到达稳定,并更好地保持平衡;在等比双粒径的组别中,细沙∶中沙=1∶1的粒度配比有利于沙波纹的发育与发展;非等比双粒径条件下的沙波纹,表现出迎风坡波长小于背风坡波长的特点;非等比双粒径和等比三粒径的组别可以更好地在高风速条件下发展。Aeolian sand ripple is a wavy microtopography caused by wind on a sandy surface.Its morphological features are mostly governed by wind speed and particle size.However,few studies have investigated the influ-ence of sand particle size distribution.As a result,the understanding of the elements influencing the morphology of sand ripples is incomplete,and the development of numerical simulation and other research methodologies is severely constrained.This research,which is based on wind tunnel experiments,sets up nine groups to observe the morphology of sand ripples at different particle size ratios.It utilizes Matlab software to extract the character-istic parameters of the sand ripples and examines their development process and saturation morphology.It is ex-pected to provide experimental data and a comparative reference,supplementing the previous work.The follow-ing are the primary conclusions:(1)More than 30%of relatively fine sand can effectively promote the forma-tion of sand ripples.The presence of relative coarse sand raises the upper limit of the sand ripple wavelength and sand ripple index.(2)The intervention of sand gradation parameters affects the complexity of the development process of sand ripples,so that the time to reach the stable saturation stage does not decrease linearly with the rise of wind speed.(3)The sand ripples created by the two-and three-size mixed sands become more intricate and inhomogeneous as the wind speed increases.The particle size ratio of fine sand to coarse sand is 1:1,which allows for faster stability and better balance.In the group of equal ratio and double particle size,the particle size ratio of fine sand to medium sand=1:1 promotes the formation and growth of sand ripples.The sand ripple un-der non-equivalent double particle size conditions reveals that the windward slope has a shorter wavelength than the leeward slope.Under high wind speeds,the non-equal ratio double particle size and equal ratio three particle size groups can develop more effectively.

关 键 词：风成沙波纹 沙粒级配 形态 风洞实验 

分 类 号：P931.3[天文地球—自然地理学]