振荡水柱防波堤气室能量转化的数值研究

Numerical Study on the Energy Transformation of OWC-breakwater

振荡水柱(OWC)防波堤是一种新型港工结构物,在消浪的同时吸收波能转化为电能。本文基于FLUENT软件建立波浪水槽数值模型对离岸式的OWC结构进行了能量转化研究。通过与规则波的理论值进行对比验证了数值波浪模型的准确性;结合能量方程,在四种不同频率波浪下对气室内水体能量变化的数值模拟结果表明:在较高频率的波浪作用下,气室内水柱的振荡和波浪的波动存在相位差;水柱下降过程中涡流动能增加,在一个波周期内,涡流动能约占气室内水体总动能的21.7%;气室内水柱下降过程中波能捕获效果优于水柱上升过程,相对于气体体积流率而言,气室内、外压力差变化为OWC防波堤结构捕获能的主要影响因素。

Oscillating Water Column Breakwater（OWC-breakwater）, a new type of costal engineering structure, in which wave attenuation happens when the Oscillating Water Column（OWC）converter absorb the wave energy for electricity. The column＇s structure directly influences its energy conversion efficiency. A numerical tank is established based on the FLUENT, and accuracy of this model is verified by the theory value in regular wave condition. Combined with energy conservation equations, the OWC-breakwater is simulated and the results show that phase differences between the surfaces wave and free water are available when the wave is in a relative high frequency. Kinetic energy loss increases when outflows begin. The energy of vortices exceeding 2.5 rad/s to the total energy is 21.7% in a wave period. The effect of power taken-off during flowing in is much better than that during flowing out. Compared with the volume rate, the pressure difference between the inner and outer OWC-breakwater is more important to the power taken-off.