发布时间：2020-03-01

文章标题：【学术成果】一篇合作作者文章在国际学术期刊 Adv Powder Technol 上发表

内容：

 

在水洞中观察到小尺度颗粒堆积体新月形状的吸引子特征

 

Yang Bin*, Su Yong, He Nan, Zhang Bo, Zhou Xiaosi*, Zhang Yang. Experimental study on the stable morphology and self-attraction effect of subaqueous barchan dunes. Advanced Powder Technology, 2020. 

 

The evolutionary process of isolated dunes under the action of a unidirectional steady water flow is

recorded from a bottom-up visual angle by optical synchronization imaging measurements. The morphological

characteristics of dunes formed from different initial sand pile configurations are analyzed by an

image-processing method. Results show that the trend of reproducing the crescent shape of the dune is

shown in all sand piles, which is independent of the initial configuration. The triangular initial sand pile is

found to be the first to stabilize to a crescent shape, whereas the square initial sand pile takes the longest

time to form a stable crescent shape. This finding is essentially due to the shape effect of the triangle,

which effectively reduces the amount of transverse moving sand particles. Based on the aspect ratio of

the barchan dune that is stable at approximately 1, we determine that the evolution time required for

the final stability of barchan dunes reproduced from different initial sand piles is approximately 200 s

within the restriction of the present closed-water-tunnel experimental condition. Moreover, a dimensionless

comparison of the profile curves of barchan dunes’ stable morphologies reveals a

‘‘streamwise–spanwise” dimension of the dune, which essentially synthesizes characteristic information

about windward face and two horns. This ‘‘streamwise–spanwise” dimension ultimately presents the

self-attraction effect of the crescent shape.