On Ripples—A Boundary Layer-Theoretical Definition

Water

Aron Roland¹  Ulrich Zanke² 

[1] BGS-ITE, Pfungstaedter Straße 20, D-64297 Darmstadt, Germany;Z & P—Prof. Zanke and Partner, Ackerstr. 21, D-30826 Garbsen, Hannover, Germany;

关键词: sediment transport;    ripples;    dunes;    bed forms;    Mars;    Titan;   

DOI  :  10.3390/w13070892

来源: DOAJ

【 摘 要 】

Once the first initial ripples have developed, they form according to the actual flow forces and sediment properties. In this paper, a semianalytical approach to determine the length of the developed ripples is presented. The theory assumes initial disturbances at the bed surface and corresponding flow separations resulting from an individual respective boundary layer. What causes the initial rhythmic perturbations is not the subject of this paper. Based on boundary layer theory, this approach explains a possible physical background for the existence and length of developed ripples in cohesion-free sediments. At the same time, the approach provides a distinction from dunes: ripples are sand waves affected by a viscous sublayer, and dunes are sand waves where this is not the case. Applications to Earth, Mars, and Titan are shown.

【 授权许可】

Unknown