Research On Aerodynamic Performance And Noise Characteristics Of Vehicle-mounted Horizontal Axis Wind Turbine

In recent years,with people’s attention to clean energy,the wind power industry has been well developed,and wind turbines have gradually entered the lives of ordinary people.With the improvement of living standards,outdoor travel is becoming more and more popular,and outdoor power consumption has become a major problem.Although small vehicle mounted wind turbine can make users realize outdoor power generation,it also has the disadvantages of low power generation efficiency and noise interference.Based on the above problems,two classical airfoils,S831 and NACA4415,are simulated in this paper.The lift coefficient,pressure distribution and sound power level distribution of the two airfoils at different angles of attack are compared.The results of numerical simulation show that NACA4415 airfoil has better aerodynamic performance and lower noise.On this basis,taking a small horizontal axis wind turbine model with NACA4415 airfoil as the research object,the corresponding simplified wind turbine model is established,and its aerodynamic performance and noise characteristics are simulated and analyzed.The results of numerical simulation are compared with the data of previous experimental models to verify the accuracy of the simulation method.The results of noise simulation show that the sound power level of suction surface is higher than that of pressure surface.In the rotating plane of the wind turbine,the noise of the blade is distributed in the area behind the leading edge,and the noise in the high power level region mainly distributes in the outer half of the blade,and presents a trend of attenuation from the blade tip to the rotating center.With the increase of axial flow distance,the sound power level in the downstream region shows a trend of gradual attenuation,but the noise influence range of the tip region is farther than that of other parts.Secondly,a kind of wind turbine with wingtip transition treatment is designed,and four wind turbines with wingtip winglets of flat plate type,pressure surface L-type,V-type and suction surface L-type are designed respectively.The effects of tip shape on the power coefficient,thrust coefficient,blade surface pressure and sound power level of the blade surface were studied under different tip speed ratios.The results show that:(1)the influence of the transition wing tip on the aerodynamic performance of the wind turbine is not obvious.The power coefficient and thrust coefficient of the wind turbine can be improved to a certain extent by the flat type,pressure surface L-type,V-type and suction surface L-type winglet,and the pressure surface L-shaped winglet has the most obvious improvement on the power coefficient of the wind turbine.At the same time,the installation of suction surface L-shaped winglet will also reduce the sound power level of wind turbine and reduce the influence range of noise.(2)With the increase of tip velocity ratio,the sound power level of blade will increase,and the influence of winglet on it will also increase gradually.Then,the influence of tip shape on the power coefficient,thrust coefficient,surface pressure and sound power level of wind turbine is studied when the inflow angle is 0 °,8 °,16 °,32 ° and 40 °.The results show that:(1)when the inlet angle is 8 °,the power coefficient and sound power level of the blade surface are significantly increased by the L-shaped winglet on the pressure surface,and the influence range of the loud power level is also enlarged.Compared with the traditional wingtips,the sound power levels of the flat,Vshaped,L-shaped winglets and transition wingtips are slightly reduced,and the distribution range of the high-level region is slightly reduced,but there is no significant change in the whole.(2)With the increase of inflow angle,the power coefficient,thrust coefficient and sound power level of all wind turbines decrease,and the influence of wingtip shape on the performance of wind turbines is gradually weakened.