【作者】 彭建军；

【导师】 张建华； 刘延俊；

【作者基本信息】 山东大学 ， 机械制造及其自动化， 2014， 博士

【摘要】 随着经济的发展,全球化石燃料日益枯竭,能源供给日益紧张,推动了海洋波浪能转换技术的发展。振荡浮子技术以其结构简单、抗风浪能力强、能量转化效率相对较高和频率响应范围宽等优点,极具开发前景。在国外,一些振荡浮子式波浪能装置已接近商业化,而国内发展相对滞后,仍在起步阶段。由于国内外海况条件差异巨大,结合我国近海波浪周期短,能量密度相对较低的特点,对振荡浮子式波浪能转换装置进行系统的自主研发是必由之路,而水动力性能研究是其中的基础性工作。本论文通过理论分析、数值计算和模型试验等研究手段,研究了振荡浮子式波浪能转换装置的水动力性能及其波浪能俘获特性。本文首先综述了波浪能发电装置的国内外研究现状和发展趋势,重点总结了振荡浮子式波浪发电装置国内外研究进展,分析和评述了现有水动力分析模型存在的主要问题,并在此基础上提出了本文的研究内容。根据振荡浮子式波浪发电装置的特点,分别应用一阶绕射理论和Froude-Krylov理论对浮子和浮筒进行波浪载荷分析；采用特征函数法和渐进匹配系数法求解一阶绕射速度势,得到了浮体垂荡和纵荡的波浪激励力、纵摇的波浪激励力矩的半解析表达式,并进行了编程求解；基于一阶辐射理论推导了等直径垂直圆柱浮体的垂荡、纵荡的附加质量系数和附加阻尼系数及纵摇的附加惯性矩系数和附加阻尼力矩系数的半解析表达式,并进行了编程求解。研究表明：在高频段,可应用于波浪能发电装置的水动力性能分析；同频率下充分考虑波浪绕射作用后浮子受到的垂向波浪力比不考虑波浪绕射时的计算结果偏低,更符合实际情况；同频率下浮筒受到的垂向波浪力仅有浮子受力的5%,浮筒的垂荡幅值是浮子垂荡幅值的1/9～1/7,揭示了振荡浮子式波浪能装置的发电机理。以水动力分析为基础,建立了浮子与浮筒的频域耦合运动方程,获得了振荡浮子式波浪能转换装置系统的频率响应函数,推导了波浪能转换系统在规则波下的俘获功率和能量俘获宽度表达式；通过频域模型研究了浮子质量、浮筒质量、浮子吃水深度、外部阻尼系数等因素对能量俘获宽度的影响。研究表明：浮子与浮筒的质量比为0.14时,装置的能量输出最大；相同结构尺寸的浮子,吃水浅的浮子俘获功率和能量俘获宽度更大；液压系统阻尼对能量输出系统的影响最大,同一装置在低频段,系统阻尼越大俘获能量越多,在高频段系统阻尼对俘获功率的影响相对较小。基于上述理论与分析,利用相似准则,按照10：1的缩尺比设计了物理模型,并在航模拖曳水池开展了模型试验研究,揭示了发电系统的阻尼、波浪的波高、周期、浮子与浮筒质量比例关系、浮体的直径等因素对装置水动力性能影响规律；模型试验结果与理论分析结果一致,进一步验证了理论分析的正确性。更多还原

【Abstract】 With the development of our society, the fossil fuels crisis turns out to be an irreversible stimulant for the development of ocean wave energy conversion technology. The technology of oscillation floater has a bright development prospect for the advantage of simple construct, strong wave resistance, higher energy conversion efficiency and wide frequency response range. Some oscillation floater wave energy devices are nearing commercialization abroad, while they are still in the initial stage with lagging development at home. Due to the huge difference in wave conditions at home and abroad, it’s the only way to develop the oscillation floater wave energy conversion device independently and systematically combined with the character of short offshore wave period and relatively low energy density of our country, and the study of the hydrodynamic performance is the basic work. This paper studies the hydrodynamic performance and the characteristics of wave energy trapping of the floating wave energy convertor via theoretical analysis, numerical calculation and model test.This paper gives an overview about the international research situation and the development tendency of the wave energy generation devices, in which the research progress of the floater wave energy generation device home and aboard is especially introduced. Then the content of this paper is pointed out based on the analysis and comments of the main problems of the existing devices.According to the features of the floater wave energy generation device, the first order diffraction theory and Froude-Krylov theory are used to analyze the wave load on the floater and pontoon. Then the solution of the first order diffraction velocity potential is found with the characteristic function method and matching asymptotic coefficient method and the semi-analytical expressions of floater’s heaving and surging wave exciting force and pitching wave excitation torque are obtained. After that, the programming solution is accomplished. Finally the equal-diameter floater’s heaving and surging added mass coefficient, added damping coefficient, pitching additional rotational inertia coefficient and additional rotational damping moment coefficient are deduced by using first-order radiation theory and the programming solution is accomplished. Studies have shown that the calculation results of the two programs are the same to that of the SESAM software at high frequency so that it can be used in the hydrodynamic performance analysis of the wave energy generation device. It is more in line with the actual situation that the vertical wave force on the floater with the full consideration of the wave diffraction effect is20%lower than that without the wave diffraction effect under the same frequency. The vertical wave force on the floater is5%of the force on the floater under the same frequency, which reveals the working mechanism of the oscillation floater wave energy device.On the basis of hydrodynamic analysis, the coupled equations of the motion of floater and pontoon in the frequency domain are established separately when only considering the heaving motion of the floater and supposing the power output system is linear and adopting a slack mooring method. The frequency response function of the floater wave energy convertor system is obtained and the system’s capture power and energy capturing width under the regular wave are deduced with the equations as well. The effects on the energy capturing width of the floater’s mass, the pontoon’s mass, the floater draught line and the external damping coefficient are studied with the frequency domain model. The results show that the device has the largest power output when the mass ratio of the floater to the pontoon is0.14. With the same size, the shallower waterline of the floater has the bigger capture power and energy capturing width. The hydraulic damping system has the biggest effect on the power output system. With the same device, more energy is captured with higher damping at low frequency while the damping has little effect on the energy capturing at high frequency.Based on the theory and analysis above, a physical model with a ratio of10:1is accomplished with the similarity criterion. A model test in a towing tank is performed for the further study on the affecting factors of the device’s hydrodynamic performance such as the damping of power system, the height of the wave, the wave period, the proportional relationship among the mass of floater and pontoon and the diameter of the floater. The results of hydrodynamic model test are basically consistent with the results of the theoretical analysis, which further verifies the correctness of the theoretical analysis.更多还原