Browse > Article
http://dx.doi.org/10.9765/KSCOE.2012.24.2.128

Parameters Analysis for Influence on the Local Scour around a Pipeline Exposed Waves and Currents  

Kim, Kyoung-Ho (Department of Civil Engineering, Chungbuk National University)
Oh, Hyoun-Sik (Department of Civil Engineering, Chungbuk National University)
Kim, Heung-Guk (Department of Civil Engineering, Chungbuk National University)
Son, Kwang-Sik (Department of Civil Engineering, Chungbuk National University)
Publication Information
Journal of Korean Society of Coastal and Ocean Engineers / v.24, no.2, 2012 , pp. 128-137 More about this Journal
Abstract
This paper deals with the local scour around a pipeline exposed to combined waves and current in the shallow water zone. To investigate the characteristics of the scour around a pipeline on the sea bed, experiments were performed according to the various pipe diameters, wave periods, wave heights, and current velocities. Wave generator and current generator were used for the experiments. Two current directions were used ; co-direction and counter direction to the waves. With the experimental results, the correlations between the scour depths and non-dimensional parameters such as Keulegan-Carpenter number(KC), Froude number(Fr), Ursell number(Ur) and velocity ratio were analysed. The relative scour depths were found obviously to be dominated by the wave component when the velocity ratio function approaches zero and those are gorverned by the current component when the velocity ratio approaches unity. Velocity ratio function was approved to be a proper parameter which is able to express the change of the scour in the combined wave and current zone. Also considering the orbital velocity and the current velocity into Fr numer and KC number respectively, scour depths show more favorable correlationship with the parameters.
Keywords
Local Scour; Fr number; KC number; Ursell number; Velocity ratio;
Citations & Related Records
Times Cited By KSCI : 2  (Citation Analysis)
연도 인용수 순위
1 김경호, 오현식, 박재성, 이호진 (2004). 해저 바닥에 놓인 관로하의 파에 의한 국부세굴특성. 대한토목학회 논문집, 24(3B), 247-257.
2 김경호, 오현식 (2011). 파랑 및 정상 흐름에 의한 해저 관로 주변의 국부세굴 특성 비교. 한국해양공학회지, 25(2), 21-28.
3 김경호, 이호진, 김완식 (2008). 파랑과 정상흐름의 공존역에서 해저관로 주변의 국부세굴. 한국해안해양공학회 논문집, 20(5), 510-521.
4 Arnskov, N.N., Fredsøe, J. and Sümer, B. M. (1993). Bed shear stress measurements over a smooth bed in three-dimensional wave-current motion, Coast. Engrg., 20, 277-316.   DOI   ScienceOn
5 Bearman, P. W. and Zdravkovich, M. M. (1978). Flow around a circular cylinder near a plane boundary, J. Fluid Mech., 89(1), 33-47.   DOI   ScienceOn
6 Bijker, E. W. and Leeuwestein, W. (1984). Interaction between pipelines and the seabed under the influence of waves and current. Seabed Mechanics, Proc. Symp. IUTAM/IUGG, Newcastle Upon Tyne, England, Dec., 235-242.
7 Chao, J. L. and Hennessy, P. V. (1972). Local scour under ocean outfall pipelines. Journal of Water Pollution control Fed., 44(7), 1443-1447.
8 Chiew, Y. M. (1990). Mechanics of Local Scour around Submarine Pipe- lines. Journal of Hydraulic Engineering, ASCE, 116(4), 515-529.   DOI
9 Chiew, Y. M. (1991(a)). Flow around horizontal circular cylinder in shallow flows. Journal of Waterway, Port, Coast and Ocean Engineering, ASCE, 117(2), 120-135.   DOI
10 Kjeldsen, S. P., et al. (1973). Local scour near offshore pipelines. Proc. Second Int. Port and Ocean Eng. under Arctic conditions Conf., 308-331.
11 Sumer and Fredsøe. (1990). Scour Below Pipelines in Waves, Journal of waterway, port, Coastal and Ocean Engineering, ASCE, 116(3), 307-323.   DOI