A Numerical Investigation Of Application Of Plasma Actuator To Control Blade Noise Of Wind Turbine

In recent years,with the rapid development of the wind turbine industry,the distance between wind farms and residential areas is getting closer,so the noise problem of wind turbines can not be ignored.With the progress of mechanical manufacturing accuracy,the mechanical noise generated by the operation of wind turbine equipment has been effectively controlled,but the aerodynamic noise of blades is still prominent.At present,some scholars at home and abroad have carried out a lot of research on the methods of suppressing the aerodynamic noise of wind turbine,and obtained some achievements.These studies mainly use passive flow control methods to suppress the aerodynamic noise of wind turbine,such as horizontal or vertical through opening,improving the aerodynamic shape of structure,increasing the surface roughness and optimizing the cross-section shape,and setting obstac les at the tail,but the active flow control method is less involved.As a new active flow control method,plasma excited flow control has its unique advantages: simple structure,no moving parts,no negative impact when not in use.In order to study how to reduce the wind pressure and noise on the surface of wind turbine blades,this article takes a 3 As the research object of MW wind turbine blade,the inhibitory effects of plasma actuator which is applied on the leading edge surface of wind turbine on the wind pressure and noise on the blade surface were studied by numerical simulation.The simulation results show that plasma can effectively control the flow field of the blade,improve the local wind pressure of the blade,and then reduce the noise of the blade,which has a wide application prospect.The specifi c contents are as follows:Firstly,the wind turbine blade model is established by using NUMECA software,and the selection principle and calculation method of relevant parameters such as grid division and boundary conditions are determined.The distribution of wind pressure and noise on the surface of the wind turbine blade without plasma excitation at rated speed is obtained by fluent calculation.It is found that the area with high noise is mainly distributed in the negative pressure area at the front edge of the blade tip pressure.Secondly,a plasma exciter is arranged near the leading edge of the blade tip pressure surface to analyze the influence of plasma excitation in different directions on the wind pressure and noise of the blade.The results show that the negative pressure peak at the front edge and the middle part of the blade pressure increase slightly,and the noise power level increases when the front edge plasma excitation is applied;the negative pressure peak at the front edge and the middle part of the blade pressur e decrease,and the noise power level decreases when the rear ed ge plasma excitation is applied.Finally,based on the preliminary understanding of the influence of plasma excitation in different directions on the wind pressure and noise of blades,the inf luence of plasma excitation in the direction of leading edge by applying 15 k V,20 k V and 25 k V peak voltage at rated speed on the wind pressure and noise of blades is analyzed.The results show that the 20 k V peak voltage plasma excitation has the best noise reduction effect on the leading edge surface of the blade.It can be seen that the higher the peak voltage of the plasma excitation is,the better the effect is.It is necessary to find a suitable peak voltage range.