岸式振荡水柱波能转换装置的时域模拟

发布时间：2018-01-11 11:17

本文关键词：岸式振荡水柱波能转换装置的时域模拟　出处：《大连理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着经济的增长、环境的恶化,世界各国对清洁、可再生能源的需求越来越迫切。波浪能是一种发展前景广阔的可再生能源,而振荡水柱波能转换装置(OWC)是目前应用最成功最广泛的波浪能转换装置之一,它具有结构简单、可靠性好,易于安装和维护等优点。本文应用高阶边界元方法(HOBEM)建立了岸式OWC的二维完全非线性时域数值模型。模型中采用源造波方法产生波浪,在气室内引入压强模型模拟气液耦合作用,引入粘性模型模拟粘性耗散。求解中采用混合欧拉-拉格朗日方法追踪瞬时水面,运用四阶龙格库塔方法更新自由水面上水质点的位置和速度势并在每一个时间步上重新划分网格。文中通过与已发表的关于平底岸式OWC与有底坡的岸式OWC的解析解、实验值和数值结果的对比,验证了模型的准确性,并通过数值计算研究了岸式OWC在规则波和不规则波作用下的水动力性能。计算结果表明：在规则波作用下,不同周期入射波对应不同的透平最佳阻尼系数,长周期波浪作用下能量转换效率对透平阻尼系数不敏感。结构尺寸的变化会影响OWC的共振频率与能量转换效率,前墙尺寸的变化对低频区的能量转换效率的影响很小,而气室宽度的改变会影响OWC在整个工作频率区间的能量转换效率。在低频区,底坡角度的增加会导致能量转换效率的减小,而高频区刚好相反。前墙水平波浪力形态取决于入射波周期,在共振频率附近一阶分量占绝对主导地位,在高频区和低频区前墙水平力的高阶分量变得比较明显。不规则波作用下,气室中点波面与气室内压强谱的谱峰频率都高于入射波谱的谱峰频率,输出功率曲线十分不稳定。
[Abstract]:With the growth of economy and the deterioration of environment, the demand for clean and renewable energy is more and more urgent. Wave energy is a kind of renewable energy with broad development prospects. The oscillating water column wave energy converter (OWC) is one of the most successful and widely used wave energy conversion devices. It has the advantages of simple structure, good reliability, easy installation and maintenance. In this paper, a two-dimensional completely nonlinear time-domain numerical model of shore OWC is established by using the high-order boundary element method (HSE). The wave generation method is used to generate waves in the model. The pressure model is introduced to simulate the gas-liquid coupling and the viscous model is introduced to simulate the viscous dissipation. The hybrid Euler-Lagrangian method is used to track the instantaneous water surface. The fourth order Runge-Kutta method is used to update the position and velocity potential of water quality points on free water surface and to remesh each time step. The accuracy of the model is verified by comparing the analytical solutions, experimental values and numerical results with the published analytical solutions of flat-bottom OWC and shore-type OWC with bottom slopes. The hydrodynamic performance of shore OWC under the action of regular and irregular waves is studied numerically. The calculated results show that under the action of regular waves, different periodic incident waves correspond to different optimal damping coefficients of turbines. The energy conversion efficiency is not sensitive to the damping coefficient of the turbine under the action of long-period wave. The change of the structure size will affect the resonance frequency and energy conversion efficiency of OWC. The change of the front wall size has little effect on the energy conversion efficiency in the low frequency region, while the change of the air chamber width will affect the energy conversion efficiency of the OWC in the whole operating frequency range. The increase of bottom slope angle leads to the decrease of energy conversion efficiency, while the high frequency region is just the opposite. The horizontal wave force shape of the front wall depends on the incident wave period, and the first order component dominates the resonance frequency. The higher order components of the horizontal force of the front wall in the high frequency region and the low frequency region become obvious. Under the action of the irregular wave, the peak frequency of the point wave surface and the pressure spectrum in the chamber are higher than the peak frequency of the incident wave spectrum. The output power curve is very unstable.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P743.2

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