风力机致动体模型研究

Study on the Actuator Body Model for Hawt

在风力机流场及其气动性能分析中,计算流体动力学(CFD)方法已受到越来越广泛的关注。近年来出现的致动模型,以在流场中添加体积力源项的形式模拟风力机与三维流场之间的相互作用,极大简化了CFD计算的网格前处理过程、降低了三维CFD计算的网格数量,为大尺度风场的工程计算提供了有效途径。本文研究了致动模型中体积力源项的分布形式,以前期建立的黏性无黏耦合模型为基础构建了新型致动体模型。该模型基于黏性无黏耦合模型提供的压力分布,在叶片真实的三维几何表面布置体积力源项,从而在源头上降低了致动模型所引入的体积力源项分布误差,提高了现有致动模型对叶片三维几何形状的计算精度。

As an important tool in analyzing the wind turbine flow field and its aerodynamic performance,the Computational Fluid Dynamics(CFD) method is receiving more and more attention.The actuator model is proposed in recent years,in which the actual wind turbine is represented by the corresponding body force source term to simulate the interaction between the wind turbine and the three dimensional(3D) flow field.The actuator model significantly simplifies the process of the grid creation and reduces the grid number to an accept level,which provides an efficient way to compute the large-scale wind farm.In this paper the distribution form of the body force source term in the actuator model is analyzed and a new actuator model named Actuator Body Model is proposed,which is mainly based on the pre-established Viscous and Inviscid Interaction(VII) Method.During the computation of the Actuator Body Model,the pressure vectors on the blade surface are provided by the VII Method and distributed on the actual geometry surface of the wind turbine blade.So the distribution error of the body force source term can be greatly reduced and at the same time the geometry accuracy of the 3D wind turbine blade is improved.