垂直轴风力机翼型涡流噪声的数值分析

为了了解垂直轴风力机翼型涡流噪声特性,以LUT翼型为研究对象,首先利用Fluent进行流场分析,流场计算选用DES湍流模型,再结合Lighthill声类比方法计算翼型周围声场,将数值模拟计算得到的气动特性相关数据与该翼型的风洞试验结果作对比分析,同时分析了不同攻角对该翼型气动噪声特性的影响,最后研究了在攻角为8°时不同雷诺数对该翼型的声压级指向性特征影响.结果表明:数值计算所得气动数据与风动试验数据拟合良好,建立的仿真模型、网格质量和边界条件合理有效;随攻角增加,翼型涡脱落从尾缘向前缘推进,同时涡流脱落强度增大,气动噪声增强;随着雷诺数的增加,翼型四周声压级先增加后减小;雷诺数与声压级关联较大,控制叶片雷诺数有助于降低叶片噪声,为该翼型适用于低噪声垂直轴叶片提供理论基础.

Numerical analysis of vortex noise of vertical axis aerofoil

To understand the vortex noise characteristics of vertical axis wind turbine aerofoil,The flow field of LUT airfoil as the research object was analyzed, by using the software Fluent. The DES turbulence model was used to calculate the flow field,and Lighthill acoustic analogy method was used to calculate the sound field around the airfoil.The aerodynamic characteristic result of the airfoil obtained from numerical simulation were compared with the wind tunnel experimental results. At the same time, the influence of different attack angle on the aerodynamic noise characteristics of the airfoil were analyzed. Finally, the effects of different Reynolds numbers on the aerodynamic noise characteristics of the sound pressure level of the airfoil was analyzed when the attack angle is 80 degree. The results show that the aerodynamic results obtained from the numerical calculation and the aerodynamic experimental results agreement well with each other. The simulation model, mesh quality and boundary conditions established are reasonable and effective. With the increase of attack angle, the vortex shedding of the airfoil pushes from the trailing edge to the leading edge, and the vortex shedding intensity increases and the aerodynamic noise increases. With the increase of Reynolds number, the sound pressure level(SPL)around the airfoil first increases then decreases. The Reynolds number is closely associated with SPL,and control the blade Reynolds number helps reduce the noise, which provides a theoretical basis for the airfoil to be suitable for low noisevertical axis blades.