基于升力面和大变形梁的风力机叶片气弹模型

Aeroelastic Modeling for Wind Turbine Blade Based on Lifting Surface Model and Nonlinear Beam Theory

为了降低风能度电成本,风力机大型化是风电行业重要的发展趋势,柔性轻质的超长叶片可能出现几何大变形。目前的风力机叶片气弹模型,其结构模型多数基于简单梁模型,对几何非线性因素的考虑较少,或者是基于二阶梁模型,气动模型则多数基于叶素动量理论。为了适应风力机大型化对结构模型和气动模型准确性的要求,本文采用一种大变形几何精确梁理论作为结构模型,完整考虑叶片大变形非线性因素;同时采用自由尾迹升力面方法作为气动模型,更准确地描述三维叶片形状对流场的影响,最终建立一个具有更高准确度的风力机叶片气弹模型。

Upscaling of wind turbine rotor is the development tendency for the wind energy industry to reduce the cost of energy. The more light-weight and thereby flexible blade may undergo large deformations in operation. The current commonly used aeroelastic models for the wind turbine blade are mostly based on linear beam theory, lacking consideration of nonlinear geometric effects.Other research works take into account the nonlinear effects by using second-order beam theory.As for the aerodynamic model, BEM model is widely adopted. To meet the requirement of more accurate structural and aerodynamic solvers for designing large-scale wind turbines, a more advanced aeroelastic model is in demand. In this paper, a nonlinear geometrically exact beam theory is implemented as the structural model, in which the blade large deformation effects are accounted. A free wake lifting surface model is used to compute the aerodynamic loads, which is capable to take into consideration of the three-dimensional deformation effects. An advanced aeroelastic model for wind turbine blade is developed by combining the structural and aerodynamic solvers.