基于等离子体激励器的风力机叶片流动控制机理及优化

The Dielectric Barrier Discharge (DBD) plasma jet is a promising new technology for flow control, reducing the aerodynamic load on large-scale wind turbines, and therefore making the light-weight design of turbines realizable. In the proposed project, the flow control and optimal design are studied for DBD actuators on flat plats, airfoils and rotating blades by means of CFD simulations, genetic algorithms and wind tunnel experiments. Firstly, the flow characteristics of the jet produced by DBD actuators on a flat plate are researched. They are used as criteria for correcting the volume force model adapted in the CFD program. Secondly, an optimization method composed of the multi-objects genetic algorithm and the CFD method is developed for DBD actuators used for controlling the blade load. Then, the flow control and load reduction made by optimized DBD actuators for airfoils and blades are studied by means of CFD simulations and wind tunnel experiments. Finally, comprehensive analysis is made on the flow control’s mechanism. The following innovations are achievable in the proposed project: ①Not only taking the airfoils but also the rotating blades of horizontal axis wind turbines as research objects for flow control produced by DBD actuators. ②A multi-variable and multi-objects optimization method is developed for the design of DBD actuators reducing the load on turbine blades. ③Profound and comprehensive understanding of the flow control’s mechanism could be gained. The expected achievements of the proposed study will contribute to the innovative design of large-scale blades with higher efficiency and less load.

流动控制能够减缓大型风力机气动载荷进而实现轻量化设计，介质阻挡放电（DBD）等离子体射流是这方面极具应用前景的一项新技术。本项目以CFD仿真、遗传算法和风洞实验为手段，以平板、翼型和旋转叶片为对象，开展DBD激励器的流动控制及优化设计研究。首先研究平板上DBD激励器射流的流场特性，并以此为依据修正CFD仿真程序中的体积力模型；其次结合多目标遗传算法和CFD仿真方法，建立针对叶片载荷控制的DBD激励器优化设计方法；接下来基于优化设计成果开展翼型上流动控制和叶片上载荷控制的CFD仿真及风洞实验研究；最后综合分析相关流动控制机理。项目的创新性体现在：①将DBD激励器的流动控制对象从翼型拓展至水平轴风力机叶片；②建立针对风力机叶片载荷控制的DBD激励器多变量多目标优化设计方法；③在流动控制机理上获得深刻而全面的新认知。研究成果将为高效低载的大型风力机叶片创新设计提供理论和方法支撑。

流动控制能够减缓大型风力机气动载荷进而实现轻量化设计，介质阻挡放电（DBD）等离子体射流是这方面极具应用前景的一项新技术。本项目以CFD数值模拟和风洞实验为主要手段，以典型风力机翼型和旋转叶片为对象，开展DBD激励器的流动控制研究。针对广泛用于风力机叶片设计的DU25和DU40翼型开展了数值模拟与风洞实验研究。进行了多个迎角下的压力分布测量和流场显示，检验了DBD激励器的流动控制效果。建立了DBD激励器用于风力机旋转叶片流动控制的实验平台，完成了对其控制效果的演示验证。研究结果表明，DBD激励器对于不同厚度的风力机翼型都能够一定程度抑制流动分离和失速，用于风力机旋转叶片的流动控制也是有效的。本项目实现了DBD激励器这一新颖的流动控制方法在风力机翼型和叶片上的研究和控制效果检验，为风力机叶片载荷的动态控制提供了新手段。