浮式立轴潮流能水轮机载体运动的频域分析

发布时间：2018-04-02 20:45

本文选题：浮式载体　切入点：垂直轴潮流能水轮机　出处：《哈尔滨工程大学》2014年硕士论文

【摘要】：潮流能在新能源开发利用中占据重要地位,是一种潜力颇大的清洁可再生能源。国内外运行的潮流能发电系统按其载体结构形式可分为漂浮式、桩柱式和重力式等,由于漂浮式潮流能电站载体适用水深范围大、安装维修方便等优点得到广泛的认可。然而,浮式潮流电站载体的水动力和运动十分复杂,若按常规的船舶或浮式海洋结构来处理,将水轮机的水动力按一定比例的阻尼直接加到载体上,不考虑水轮机与载体的流场相互干扰,这种粗略的估计方法所导致的偏差可能很大。因此,研究带有潮流能水轮机的浮式载体在风浪和急流中的水动力及其运动特性是潮流能电站设计的关键问题之一。本文研究浮式载体带有立轴潮流能水轮机的水动力学问题,在势流理论的框架下建立波浪中带有水轮机的浮式载体的运动方程,研究载体加水轮机的水动力及其运动的计算方法,探讨水轮机对载体水动力及运动的影响规律。首先,概括了潮流能的利用、潮流能发电站以及立轴潮流能水轮机技术的发展现状,对立轴水轮机的水动力计算理论以及一般浮体在波浪中运动的势流理论进行了综述;然后,基于牛顿第二定律,将运动流体中水轮机的受力作为外载荷加到载体上,建立了浮式载体加水轮机在波浪中的一般运动方程。对于微幅波浪的情况,研究浮式载体加水轮机运动方程的频域求解方法:将载体在规则波中的六自山度运动分解为辐射问题和绕射问题,获得规则波中载体水动力系数的速度势表达以及频域运动微分方程;对于立轴水轮机随浮体在波浪中运动的受力问题,基于切片理论建立直叶片水轮机的水动力模型,并表达为水动力导数的形式。作为本文带有水轮机的浮体水动力学模型和六自由度频域求解方法的应用,不失一般性,研究典型的圆盘型浮式载体在规则波中作纵荡和纵摇运动的问题。首先列出立轴水轮机在水流中作纵荡和纵摇运动时的受力表达式,进而导出了载体加水轮机纵荡、纵摇两个自由度的运动方程。数值计算时,以水轮机处于不旋转的状态作为研究算例,分别取水轮机叶轮处于0°、45°和90°位置角作为研究对象。将水轮机在均匀流中受力的CFD模拟结果,拟合为叶轮各个位置角时水轮机的水动力导数。对载体加水轮机的频域运动方程采用MATLAB语言进行编程求解,分别求得了无水轮机载体、载体加水轮机纵荡和纵摇运动的水动力和运动幅值数值结果;研究了水轮机在不同叶轮位置角时对载体的水动力和运动幅值产生不同程度影响的规律。
[Abstract]:Tidal energy plays an important role in the development and utilization of new energy, and it is a kind of clean and renewable energy with great potential.The domestic and foreign tidal current power generation system can be divided into floating type, pile type and gravity type according to its carrier structure. Because of its wide range of water depth and convenient installation and maintenance, floating tidal power station has been widely recognized.However, the hydrodynamic force and motion of the carrier of floating tidal power station are very complicated. If the hydrodynamic force of hydraulic turbine is treated according to the conventional ship or floating ocean structure, the hydrodynamic force of hydraulic turbine is directly added to the carrier according to a certain proportion of damping.Without considering the interference between turbine and carrier, the deviation caused by this rough estimation method may be very large.In this paper, the hydrodynamic problem of floating carrier with vertical current turbine is studied. The equation of motion of floating carrier with turbine in wave is established under the framework of potential flow theory.The calculation method of hydrodynamic force and motion of carrier turbine is studied, and the influence of hydraulic turbine on hydrodynamic force and motion of carrier is discussed.Based on Newton's second law, the general equation of motion of floating carrier and turbine in wave is established by applying the force of turbine in moving fluid as external load to the carrier.For the case of micro-amplitude wave, the frequency domain solution method of the motion equation of floating carrier and hydraulic turbine is studied. The six-degree motion of carrier in regular wave is decomposed into radiation problem and diffraction problem.And expressed in the form of hydrodynamic derivatives.In this paper, the force expressions of vertical hydraulic turbine in longitudinal and pitching motions in water flow are first presented, and the equations of motion for vertical swing and pitching of vertical turbine with carrier are derived.In numerical calculation, the unrotating state of the turbine is taken as an example, and the angle of the turbine impeller in the position of 0 掳45 掳and 90 掳is taken as the object of study respectively.The CFD simulation results of the turbine acting in uniform flow are fitted to the hydrodynamic derivatives of the turbine at various angles of the impeller.The frequency-domain motion equation of carrier turbine is solved by MATLAB language, and the hydrodynamic and motion amplitude of hydrodynamic and pitching motion of hydro-turbine carrier and carrier turbine are obtained respectively.The effects of different impeller position angles on the hydrodynamic force and motion amplitude of the hydraulic turbine are studied.
【学位授予单位】：哈尔滨工程大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TK730.1

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