Stegner A, Wesfreid J E
Laboratoire de Météorologie Dynamique, ENS, 24 Rue Lhomond, 75231 Paris, France.
Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 1999 Oct;60(4 Pt A):R3487-90. doi: 10.1103/physreve.60.r3487.
We have performed an experimental study on the evolution of sand ripples formed under the action of an oscillatory flow. An annular sand-water cell was used in order to investigate a wide range of parameters. The sand ripples follow an irreversible condensation mechanism from small to large wavelength until a final state is reached. The wavelength and the shape of these stable sand patterns are mainly governed by the fluid displacement and the static angle of the granular media. A strong hysteresis affects the evolution of steep ripples. When the acceleration of the sand bed reaches a critical value, the final pattern is modified by the superficial fluidization of the sand layer.
我们对振荡流作用下形成的沙纹演变进行了一项实验研究。为了研究广泛的参数范围，使用了一个环形沙水试验槽。沙纹遵循从小波长到大波长的不可逆凝聚机制，直至达到最终状态。这些稳定沙纹图案的波长和形状主要由流体位移和颗粒介质的静态角度决定。强烈的滞后现象影响着陡峭沙纹的演变。当沙床加速度达到临界值时，最终图案会因沙层的表面流化而改变。
