金字塔沙丘风洞流场结构的实验研究─—兼论金字塔沙丘发育模式  

EXPERIMENTAL STUDY ON THE STRUCTURE OF WIND-TUNNEL FLOW PATTERN FOR PYRAMID DUNES:GIVING CONSIDERATION TO A MODEL FOR PYRAMID DUNE FORMATION

作　　者：李志忠[1] 陈广庭[1] 

机构地区：[1]新疆师范大学地理系,中国科学院兰州沙漠研究所

出　　处：《中国沙漠》1995年第3期227-236,共10页Journal of Desert Research

基　　金：国家"八五"科技攻关项目

摘　　要：金字塔沙丘以其大尺度、金字塔形态和放射状伸展的沙臂为特征。本文以三面体金字塔沙丘模型的风洞流场实验为基础，结合野外观测资料，发现金字塔沙丘的流场结构，特别是背风侧剖面流场除具有一般新月形沙丘的流场结构特点外，还有特殊的“Ｅ”型流场结构，正是这种多向风信产生的复杂流场结构形成具有凹面形态的多角形金字塔沙丘。据此，作者提出了由新月形沙丘（包括其复合形态）演化为金字塔沙丘的发育模式。Pyramid dunes are characterized by their large size,pyramidal morphology, and radiatingsinuous arms. Based on the experiments for the wind-tunnel flow patterns of trihedral pyramid dunemodels,combined with field observations,we found that apart from the flow pattern like that existingat the surface on the barcan dunes,there are particular'E'flow pattern at the surface on the lee slopeof the pyramid dune model.It is the complicated flow patterns which are resuIted from multi-directional wind regime that makes the multi-angle pyramid dune with concave faces.On thesegrounds,a new model for pyramid dune formation by development of barcan dune(including theircompound forms)has been advanced in this paper.

关 键 词：金字塔沙丘 流场结构 发育模式 沙丘 风洞流场 

分 类 号：P931.3[天文地球—自然地理学]