The 12th International Conference on Hydrodynamics
18 – 23 september 2016, Egmond aan Zee, The Netherlands
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INSIGHT OF VORTEX STRUCTURE NEAR SUBMERGED RECTANGULAR DIKE DUE TO PROPAGATION OF SOLITARY WAVE


Go-down ichd2016 Tracking Number 22

Presentation:
Session: Hydrodynamics in Ocean I
Room: Room 3
Session start: 10:30 Mon 19 Sep 2016

Chang Lin   chenglin@nchu.edu.tw
Affifliation: Department of Civil Engineering, National Chung Hsing University, Taichung, Taiwan

Wei-Ying Wong   wongweiying25@gmail.com
Affifliation: Department of Civil Engineering, National Chung Hsing University, Taichung, Taiwan

Ming-Jer Kao   d9362202@mail.nchu.edu.tw
Affifliation: Department of Civil Engineering, National Chung Hsing University, Taichung, Taiwan

Chia-Feng Hu   g104062217@mail.nchu.edu.tw
Affifliation: Department of Civil Engineering, National Chung Hsing University, Taichung, Taiwan

Hwung-Hweng Hwung   hhhwung@mail.ncku.edu.tw
Affifliation: International Wave Dynamics Research Center, National Cheng Kung University, Tainan, Taiwan

Yun-Ta Wu   ytwu@mail.ncku.edu.tw
Affifliation: International Wave Dynamics Research Center, National Cheng Kung University, Tainan, Taiwan

Rajkumar Venkatesh Raikar   rvraikar@gmail.com
Affifliation: Department of Civil Engineering, KLE College of Engineering and Technology, Belgaum, India

James Yang   james.yang@vattenfall.com
Affifliation: Hydraulic Engineering, Department of Civil Engineering, Royal Institute of Technology, Stockholm, Sweden


Topics: - Hydrodynamics in ocean, coastal and estuary engineering

Abstract:

This paper presents the detailed flow structures above a rectangular dike and on its downstream side as well as in the breaking backwater wave due to passing of a solitary wave measured experimentally, using particle-trajectory flow visualization technique and high-speed particle image velocimetry (HSPIV). The ratio of wave height to water depth and the submergence ratio considered in the study were respectively, 0.5 and 0.71. Initially, the evolution of two vortices at the two top edges of the dike are noticed which grow in size. The vortex developed at the trailing edge is found to get entrained into the primary vortex that emanated from the leading edge and moved downstream. Due to combination of two vortices a surface wave is developed which breaks as an effect of the movement of solitary wave below the surface wave in the form of a jet flow. The breaking of the surface wave pushes the primary vortex to the bottom thereby generating another vortex near the bottom, which rises and sheds after striking the downstream face of the dike. Fur-ther, the velocity fields drawn above the rectangular dike and near the breaking backwater surface wave support the formation of series of vortices.