Numerical analysis of vortex noise of vertical axis aerofoil
YANG Congxin1,2,3,NING Jianbin1*,LI Shoutu1,2
1. School of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China; 2. Gansu Wind Turbine Engineering Technology Research Center, Lanzhou, Gansu 730050, China; 3. Key Laboratory of Fluid Machinery and Systems, Lanzhou, Gansu 730050, China
Abstract：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.
