Next Article in Journal
Study on the Decontamination Effect of Biochar-Constructed Wetland under Different Hydraulic Conditions
Next Article in Special Issue
Evaluation of Incipient Motion of Sand Particles by Different Indirect Methods in Erosion Function Apparatus
Previous Article in Journal
Understanding China’s Urban Rainstorm Waterlogging and Its Potential Governance
Previous Article in Special Issue
Reservoir Sediment Management Using Artificial Neural Networks: A Case Study of the Lower Section of the Alpine Saalach River

On Ripples—A Boundary Layer-Theoretical Definition

by 1,2,* and 3
Z & P—Prof. Zanke and Partner, Ackerstr. 21, D-30826 Garbsen, Hannover, Germany
TU Darmstadt, D-64289 Darmstadt, Germany
BGS-ITE, Pfungstaedter Straße 20, D-64297 Darmstadt, Germany
Author to whom correspondence should be addressed.
Academic Editor: Sameh Kantoush
Water 2021, 13(7), 892;
Received: 26 January 2021 / Revised: 10 March 2021 / Accepted: 13 March 2021 / Published: 24 March 2021
(This article belongs to the Special Issue Sediment Transport and River Morphology)
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. View Full-Text
Keywords: sediment transport; ripples; dunes; bed forms; Mars; Titan sediment transport; ripples; dunes; bed forms; Mars; Titan
Show Figures

Figure 1

MDPI and ACS Style

Zanke, U.; Roland, A. On Ripples—A Boundary Layer-Theoretical Definition. Water 2021, 13, 892.

AMA Style

Zanke U, Roland A. On Ripples—A Boundary Layer-Theoretical Definition. Water. 2021; 13(7):892.

Chicago/Turabian Style

Zanke, Ulrich, and Aron Roland. 2021. "On Ripples—A Boundary Layer-Theoretical Definition" Water 13, no. 7: 892.

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

Back to TopTop