三角帆海上风力发电设备帆角自动迎风对准系统力学问题

Lateen offshore wind power generation is a new kind of promising clean energy equipment aiming at marine development, however, the variation in wind direction and velocity at any time makes it difficult to guarantee the upwind area not decrease , and even lead to the presence of losing velocity, thus, it leads to the efficiency of power generation decrease and even make the system hard to run.Lateen automatic upwind system mainly compares and revises the pressure coefficient which precise calculated of the unsteady turbulent field and the pressure coefficient measured by measurement sensors, then gets the selected data that has already overcome both shortcomings. Through the optimal design of lateen motion control software to control mechanical actuators, readjusts the angle of lateen to achieve the largest upwind area, forms closed loop system, makes it produce the maximum efficiency of power generation. To achieve the object, the problem of inaccurate calculation of lateen positive and negative pressure coefficient based on the current turbulent model must be solved firstly, which involves the modification of the anisotropy of pulsating turbulent kinetic energy near the laminar turbulent region on the lateen surfaces, and also involves the correct calculation of the pulsating turbulent kinetic energy、the central recirculation zone and the recirculation length near the obstacles. The task will measure the pressure coefficient (with the existence of the interruption of wind pulsation), and it supplement with the predicted result of computational fluid dynamics (Utilizing LES needs pretty huge computer resource, and RANS has the modification of approximation ), thus to identify the optimal adjusted angle of lateen, and to make the largest pressure difference between the positive and negative surface at each instantaneous in inherent working time. The project develops large size lateen prototype on the basis of theoretical research，builds the lateen wind power simulation platform based on theoretical basis、 experimental prototype、control software、large-scale experimental pool，verifies the effectiveness of the theoretical research result、experimental prototype and control software, to provide the foundation of the practical application of lateen offshore wind power generation system.

三角帆海上风力发电是针对海洋开发的新型有前景的清洁能源设备，但海上风速和风向随时随地变化使得三角帆难以做到保证迎风面积不减小甚至失速等情况，从而导致发电效率降低甚至难以运行。三角帆自动迎风对准系统主要由非稳态湍流场压力系数的精确计算和传感器测得的压力系数进行对比修正，得到克服二者弊病的选择数据。通过三角帆船运动控制软件控制机械执行机构，重新调整三角帆角度实现最大迎风面积，构成闭环系统，使其产生最大的发电效率。为达到此目的，必须解决现有工程模型对三角帆正反面压力系数计算不准确的力学问题。课题将对压力系数进行测量，并和计算流体力学结果进行相互补充，确定三角帆表面调整的最佳角度。本项目在理论研究的基础上，研制大尺寸实验样机，建立以理论基础、实验样机、控制软件、大尺寸实验水池为支撑的三角帆风力发电仿真模拟平台，检验理论研究结果、实验样机以及控制软件的有效性，为三角帆风力发电设备的实际应用奠定基础。

三角帆海上风力发电是针对海洋开发的新型有前景的清洁能源设备，但海上风速和风向随时随地变化使得三角帆难以做到保证迎风面积不减小甚至失速等情况，从而导致发电效率降低甚至难以运行。本项目针对这一问题，提出对三角帆自动迎风对准系统进行研究。通过理论分析，建立起风力机的理论模型。应用商用CFD软件，对风力机的叶片提出改进，对比研究了新型叶片和传统叶片之间的气动性能差异，并对优化风力机发电效率给出建议。对传统的单层叶片风力机和双层叶片的风力机的气动性能、自启动性能和发电效率进行了数值仿真和实验研究，总结了双层叶片对风力机对自启动性能及发电效率的影响。研究发现在低尖速比下双层叶片风机的发电效率远大于单层叶片风机，高尖速比下相反。双层叶片风机叶片间距S对自启动性能影响显著，风机的叶片间距S存在着界限，当叶片间距S>12cm，最小启动风速与单层叶片风机相同；当叶片间距S<12cm时，随着叶片间距S的减小，自启动性能增加。.为了进一步提高风机的发电效率，基于叶片空气动力学分析，提出一套以叶片当地流场的实时信息为依据，反馈调节叶片桨距角的方法，用以提高垂直轴风力发电机（VAWT）的风能利用效率以及低尖速比下VAWT的启动性能。研究发现，合适的实时反馈调节桨距角的方案，能够极大减少了VAWT在低尖速比下叶片表面涡脱落和流动分离的发生，从而显著提升启动性能。同时，增大VAWT在高尖速比下叶片两侧的压力差值，从而提升风能利用效率。并且风能利用效率普遍达到40%以上，最高为50.413%。相对于零桨距角的情况，相对提升效率基本达到20%以上，最高的相对提升达到了74.645%。