Effect of Lee‐Wake on Scour Below Pipelines in Current
Publication: Journal of Waterway, Port, Coastal, and Ocean Engineering
Volume 114, Issue 5
Abstract
The results of an investigation of the effect of lee‐wake on scour below pipelines in currents are reviewed. The subject is investigated both experimentally and numerically. The experiments show that the scour downstream of the pipe is apparently governed by the action of an organized wake flow, which is an agglomeration of large‐scale vortices which are shed from the pipe and steadily convected downstream. The experimental results lead to a clear understanding of the effect of lee‐wake on the scour phenomenon. In the numerical part of the study the so‐called cloud‐in‐cell method is employed to predict the flow. The results appear to reveal almost all the features of the organized wake flow shown by the experiments. The theoretical calculations demonstrate that the time average bed shear stress is not a suitable parameter to work with in mathematical‐model studies of lee‐wake scour.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Achenbach, E., and Heinecke, E. (1981). “On vortex shedding from smooth and rough cylinders in the range of Reynolds numbers to .” J. Fluid Mech., 109, 239–251.
2.
Bijker, E. W., and Leeuwenstein, W. (1984). “Interaction between pipelines and the seabed under the influence of waves and currents.” In Seabed Mechanics, B. Denness, ed., Int. Union of Theoretical and Appl. Mech. Conf., Graham and Trotman, Gettysburg, Md.
3.
Engelund, F. and Hansen, E. (1967). A monograph on sediment transport in alluvial streams. Teknisk Forlag, Copenhagen.
4.
Fredsøe, J. (1974). “On the development of dunes in erodible channels.” J. Fluid Mech., 64, 1–16.
5.
Hansen, E. A., Fredsøe, J., and Ye, M. (1986). “Two‐dimensional scour below pipelines.” Proc. 5th Int. Symp. on Offshore Méch. and Arctic Engrg., ASME, Tokyo, Japan, April 13–17, 670–678.
6.
Ibrahim, A., and Nalluri, C. (1986). “Scour prediction around marine pipelines.” Proc. 5th Int. Symp. on Offshore Mech. and Arctic Engrg., ASME, Tokyo, Japan, April 13–17, 679–684.
7.
Jensen, B. L. (1987). “Large‐scale vortices in the wake of a cylinder placed near a wall.” Proc. 2d Int. Conf. on Laser Anemometry, Glasgow, Scotland, Sept. 21–23, 153–164.
8.
Leeuwenstein, W. and Wind, H. G. (1984). “The computation of bed shear in a numerical model.” Proc. 19th Coastal Engrg. Conf., 2, Sept. 3–7, 1685–1702.
9.
Schewe, G. (1983). “On the force fluctuations acting on a circular cylinder in cross‐flow from subcritical up to transcritical Reynolds numbers.” J. Fluid Mech., 133, 265–285.
10.
Stansby, P. K., and Dixon, A. G. (1983). “Simulation of flows around cylinders by a Lagrangian vortex scheme.” Appl. Ocean Res., 5(3), 167–178.
Information & Authors
Information
Published In
Copyright
Copyright © 1988 ASCE.
History
Published online: Sep 1, 1988
Published in print: Sep 1988
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.