【作者】 刘臻；

【导师】 史宏达； 李华军； 玄汎洙；

【作者基本信息】 中国海洋大学 ， 港口、海岸及近海工程， 2008， 博士

【摘要】 岸式振荡水柱波能发电装置是目前世界上应用最为广泛的波能转换利用装置。对该类波能转换装置的全面深入研究,可为开发设计更为高效的波能转换与利用装置提供指导,对解决日益严峻的能源和环境问题具有重要意义。本文以岸式振荡水柱波能发电装置的实用化开发为背景,采用物理模型试验和数值模拟相结合的方法对该类波能发电装置进行了系统的研究。对气室结构的物理模型试验研究,发现了气室内自由水面振荡波幅、相对压强及输气管内空气流速与入射波要素的变化关系,考察了气室宽度、前墙吃水深度、前墙厚度、底坡坡角及气室顶部开口形式在不同的波周期区对气室波能俘获能力的影响,在此基础上遴选出影响气室工作性能的主要参量,并建议根据不同气室结构和参量选择二、三维数值计算模式。本研究构建了基于水气两相VOF模型的二、三维数值波浪水槽,采用PLIC法进行自由水面追踪方法有效可靠,波浪周期、波长及波高等参量的计算值与理论解析解基本一致。气室结构的二维数值模拟发现,相对波幅会在入射波周期范围内形成三个具有不同分布特征的区域:短周期区,峰值区及长周期区。气室宽度较小时,气室墙前水深、气室前墙吃水深度、气室前墙厚度及海底坡角对气室性能具有一定的影响;气室宽度较大时,相对波幅在入射波周期范围内不存在峰值区,且上述各参量对气室波能俘获能力的影响则较小。与二维计算及试验结果相比,三维数值波浪水槽能够更为准确地预测气室内相对波幅、相对压强及输气管内流速。气室宽度、气室长度及输气管管径对气室工作性能的影响较大,输气管管长及其装配位置对气室波能转换效率的影响则较小。波浪聚集装置能够在长周期区提高气室—输气管系统的工作性能,多孔介质模型可模拟空气透平对气室—输气管系统的压降作用及其对输气管内流量变化的影响。本文建立了基于多重参考系模型冲击式透平的三维数值模拟方法,确定了计算中应采用的湍流计算模型,网格类型与网格数范围。与试验结果的比较表明,三维数值模拟对透平工作性能的计算结果优于二维模式。本研究通过数值模拟得到了透平内空气流场及动叶片表面压力分布规律,给出了动叶片数,透平径间比,动叶片入射角,动叶片装置角,透平轮毂比及动叶片外径间隙的最佳设计值,提出了在动叶片顶端安装环形盖板及设置动叶片弯扭角的优化方案。更多还原

【Abstract】 Oscillating Water Column (OWC) wave energy convertor for electricity generation is most widely used in the world. The investigation of the OWC wave energy convertor can provide guidance to the research and design of the highly efficient wave energy converting and utilizing system, which is also extremely important to solving the nowadays energy and environmental crisis. In order to develop the OWC wave energy converting system practically, the physical model experiments and numerical simulations are employed to investigate the wave energy converting device systemically.In the experimental study on the air chamber, it is found that the oscillating amplitudes of the free surface and relative pressure in the chamber and the air flow velocities in the duct are related to the incident wave parameters. The effects of the chamber width, the draft of the chamber skirt, the thickness of the chamber skirt, bottom slope and the opening styles on the chamber performance are studied. The key parameters are selected for the numerical simulations, which will be different according to the variation of the chamber profiles.The 2D and 3D numerical wave tanks are established based on the two-phase air-water VOF model. The free surface methods applied in the thesis are validated with the experimental results. The numerical results of the wave parameters such as wave periods, wave lengths and wave heights show good agreement with the analytical solutions.In the 2D numerical simulation of the air chamber, the distributions of the relative amplitudes against the incident wave period are divided into the short-period zone, peak-value zone and long-period zone. The still water depth in front of the chamber, the draft of the chamber skirt and the thickness of the chamber skirt have effects on the chamber performance when the chamber width is small. The peak-value zone will disappear when the chamber width is large, and the effects of the above parameters are minor.The 3D numerical wave tank can predict the relative amplitudes and the relative pressure in the chamber and the air velocities in the duct more precisely than the 2D numerical wave tank. In the 3D numerical study, the effects of the chamber width, the chamber length and the duct diameter on the chamber performance are evident. The duct length and its installed position have little influence on the chamber wave energy converting ability. The wave focusing devices can improve the chamber performance in the long period zone. The porous media model can be applied to simulate the pressure loss in the chamber-duct system induced by the impulse turbine, which also has effects on the air flow rate in the duct.The 3D numerical predicting method on the impulse turbine based on the multiple reference frame model is established in the paper. The turbulence model, mesh type and mesh numbers are selected. The comparison with experimental results shows that the 3D numerical results are better than that of the 2D calculation. The air flow field and pressure distribution in the turbine are obtained. The optimal design value of the rotor blade number, the gap ratio of the turbine, the blade inlet angle, the blade setting angle, and the hub-to-tip ratio and the tip clearance are predicted in the calculation. The optimizing design of the ring-type plate covering the blade top and the staggered angle of the rotor blade are also provided.更多还原