风力发电机叶片的雾凇覆冰数值模拟

Numerical simulation on rime icing of wind turbine blades

摘要:

为了解风力发电机叶片覆冰情况,以某型300 kW风力发电机叶片为研究对象,根据切片-重构的思想,将叶片划分为有限个截面,基于叶片覆冰的物理过程,采用边界元法对风力发电机叶片的空气流场进行计算；采用拉格朗日法分析计算水滴在叶片表面的碰撞过程；通过迭代计算和冰形重构模拟覆冰增长过程,从而建立风力发电机叶片三维雾凇覆冰增长模型；基于数值模型仿真分析不同风速对叶片雾凇覆冰增长的影响。结果表明:雾凇覆冰增长同时受到外部环境和叶片翼型的影响,覆冰积聚在叶片的前缘,从叶根到叶中部覆冰增长缓慢,从叶片中部到叶片尖部覆冰增长迅速,随着风速的增加,覆冰厚度和覆冰面积随之增加,覆冰区域从背风面向迎风面移动,且风速的变化对叶片中部到尖部覆冰的影响更为显著。

Abstract:

In order to investigate wind turbine blade icing, this paper takes the blades of 300 kW wind power equipment as research object. According to a slicing-reconstructing idea, the blades were divided into finite sections. Based on the physical process of blade icing, the boundary element method was adopted to calculate the flow field of wind turbine blade icing. The Lagrangian method was used to numerically calculate the process of water droplets colliding with the blade surface. The ice growth process was simulated through iterative calculation and ice shape reconstruction, and a three-dimensional rime ice growth model of wind turbine blades was thus obtained. The influence of different wind speeds on the rime ice growth of blades was analyzed on the basis of numerical simulation. Results show that rime ice growth was affected by both external environment and blade airfoil. Ice accumulated at the leading edge of the blade; the icing thickness increased slowly from the root to the middle of the blade, and rapidly from the middle to the tip of the blade. As the wind speed increased, the icing thickness and ice coverage area increased, and the ice-covered area moved from leeward to windward. In addition, wind speed had greater impact on the icing of blades from the middle to the tip.