Experimental and numerical study of a circular OWC with a U-shaped duct for wave energy conversion in long waves: Hydrodynamic characteristics and viscous energy loss
Experimental and numerical study of a circular OWC with a U-shaped duct for wave energy conversion in long waves: Hydrodynamic characteristics and viscous energy loss
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DOI：
10.1016/j.renene.2023.06.022
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发表时间：
2023
期刊：
影响因子：
8.7
通讯作者：
Cong Xu;Yu-Lu He;Yu-Ping Yao;J. Zuo
中科院分区：
文献类型：
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作者：
Cong Xu;Yu-Lu He;Yu-Ping Yao;J. Zuo
本文介绍了一种用于长波波能转换的桩式U形管道圆形振荡水柱装置（圆形U-OWC）的实验和数值研究。在波浪水槽中，对圆形U-OWC模型和相同闸室尺寸的常规OWC模型在不同波浪条件下的性能进行了对比试验。不同尺寸的节流孔用于模拟动力输出（PTO）。测量了气动功率、PTO阻尼系数和入射波的散射。通过实验验证了基于RANS方程的湍流封闭模型的正确性。利用该数值模型研究了燃烧室内自由液面的空间不均匀性和U形管道内的粘性能量损失。据发现，对于长波，圆形U-OWC装置比传统OWC装置的效率高几倍，并且与传统OWC装置相比，气动室内的晃动效应显著降低。研究还发现，进入U形通道的能量有相当一部分以粘性损失的形式耗散，为减小装置的粘性损失，提出了U形通道的设计建议。
This paper presents an experimental and numerical study of a pile-type circular oscillating water column device with a U-shaped duct (circular U-OWC) for wave energy conversion in long waves. In the experiments, the circular U-OWC model and a conventional OWC model of identical chamber dimension was compared in a wave flume under various wave conditions. Orifices of different sizes are used to simulate the power-takeoff (PTO). The pneumatic power, PTO damping coefficient, and the scattering of the incident waves are measured. A RANS equation based numerical model with a modified k-ω SST turbulence closure is validated using the experiment. The numerical model is utilized to investigate the spatial non-uniformity of the free surface inside the chamber, and the viscous energy loss in the U-shaped duct. It is found that for long waves, the circular U-OWC device is several times more efficient than a conventional OWC device, and the sloshing effect inside the pneumatic chamber is significantly reduced compared to a conventional OWC device. It is also found that a significant amount of energy entering the U-shaped duct is dissipated in viscous loss, recommendations on U-shaped duct design are given to help reduce the viscous loss of the device.