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浙江大学学报(工学版)
Journal of ZheJiang University (Engineering Science)  2021, Vol. 55 Issue (7): 1308-1316    DOI: 10.3785/j.issn.1008-973X.2021.07.010
    
Study of flow characteristics around row of oscillating water column pile under regular waves
Cong-hao XU1,2(),Yu YAO1,2,*(),Ting GUO2,Zheng-zhi DENG3
1. Hunan Provincial key Laboratory of key Technology on Hydropower Development, Changsha 410014, China
2. School of Hydraulic Engineering, Changsha University of Science & Technology, Changsha 410114, China
3. Ocean College, Zhejiang University, Zhoushan 316021, China
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Abstract  

A numerical wave tank was developed based on Reynolds-Averaged Navier-Stokes equations with k? $\omega$ turbulence closure. The accuracy of numerical model was first verified by laboratory experiments. Then, the model was used to simulate the flow field characteristics near the device under the effect of regular waves. The vortex characteristics and its implication to local erosion mechanism were analyzed. Results show that under tested conditions, a concave horseshoe vortex is formed at the toe of the oscillating water column pile and wake vortices are formed around the structure. The strength of the horseshoe vortices decreases with the increase of the Keulegan-Carpenter (KC) number, and the strength of the wake vortices increases with the increase of the KC number. The horseshoe vortices are too weak to be the main factor in sediment scour at the range of KC number in this simulation, while the strong wake vortices are likely to be a main control factor of sediment initiation of motion, transport and scour near the pile foundation.

Key words： wave energy      row of piles      wake vortices      Navier-Stokes equations      regular wave     
Received: 16 May 2020      Published: 05 July 2021
CLC:  TV 139.2  
Fund:  水能资源利用关键技术湖南省重点实验室开放研究基金资助项目（PKLHD201706）
Corresponding Authors: Yu YAO     E-mail: conghaox@163.com;yaoyu821101@163.com
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Cong-hao XU
Yu YAO
Ting GUO
Zheng-zhi DENG
Cite this article:

Cong-hao XU,Yu YAO,Ting GUO,Zheng-zhi DENG. Study of flow characteristics around row of oscillating water column pile under regular waves. Journal of ZheJiang University (Engineering Science), 2021, 55(7): 1308-1316.

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https://www.zjujournals.com/eng/10.3785/j.issn.1008-973X.2021.07.010     OR     https://www.zjujournals.com/eng/Y2021/V55/I7/1308


排桩式波浪能发电装置附近流场特性研究

基于雷诺时均Navier-Stokes方程和k?ω湍流模型，研究单排桩式振荡水柱式波浪能发电装置在规则波作用下的桩基附近流场特性. 通过物理模型实验验证所建数值波浪水槽的准确性. 模拟规则波作用下装置附近的流场特性，分析装置附近的涡特征以及其对装置附近泥沙冲刷情况的潜在影响. 结果表明，测试工况下，在桩式振荡水柱装置桩柱体的桩基附近观察到马蹄涡和尾涡现象，马蹄涡强度随着Keulegan–Carpenter（KC）数的增大而减小，尾涡强度随着KC数的增大而增大. 马蹄涡因强度过小，在模拟的KC数范围内不是装置桩基泥沙冲刷的主要因素，高强度的尾涡很可能成为装置桩基附近泥沙起动、输运和冲刷的重要影响因素.


关键词： 波浪能,  排柱,  尾涡,  Navier-Stokes方程,  规则波 
Fig.1 Setting of experiment and numerical model cell
Fig.2 Comparison of time-series free surface elevations between numerical simulations and experimental measurements
Fig.3 Flow fields on vertical plane at different phases under test condition $T = 0.{\rm{7 }}\;{\rm{s}} $
Fig.4 Flow fields on vertical plane at different phases under test condition $T = 1.5{\rm{ }}\;{\rm{s}} $
Fig.5 Flow fields on horizontal plane at different phases under test condition T = 0.7 s
Fig.6 Flow fields on horizontal plane at different phases under test condition T = 1.5 s
T/s KC数 S1 S2 S3
0.7 1.02 0.061 4 0.0130 0.003 78
1.5 1.53 1.286 0 0.4830 0.003 21
Tab.1 Strengths of horseshoe vortex and wake vortex for different test conditions.
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