Experimental Study On A Vertical Axis Wind Turbine With Frustum-shaped Wind Gathering Equipment

This study is committed to design a straight-wing vertical axis wind turbine with frustum-shaped wind gathering equipment installed upper and lower ends of it, the purpose of which is to improve the utilization of wind energy of straight-wing vertical axis wind turbine. Using the apparatus to collect a larger area to the wind and to improve the wind speed inflow, the purpose is to increase the output power of the wind turbine. The wind tunnel experiment was conducted in order to verify the effectiveness of the device gathering wind and to ascertain the impact of wind gathering equipment to output power of vertical axis wind turbine. A straight-wing vertical axis wind turbine model was manufactured through the whole experimental design, the airfoil of blade is NACA0018, number of blades is4, height of blade is0.5m, and diameter of wind turbine is0.6m. A frustum-shaped wind gathering equipment is designed by the wind turbine model, which main parameters of it consists of the following parts, two angles of frustum-shaped wind gathering equipment is20degree and30degree; three diameters of it is0.4m,0.6m and0.7m; the distance between frustum-shaped equipment and wind turbine is0m,0.02m,0.04m. Wind speed at6m/s and lOm/s were selected through the test. And the test was implemented at the low speed wind tunnel installed in College Engineering of Northeast Agricultural University. Thus the following main conclusions under the experimental conditions can be obtained:1) Power coefficient of wind turbine can be effectively enhanced while the frustum-shaped wind gathering equipment is installed at some certain structural parameters, and up to24%.2) The influence of distance between frustum-shaped device and wind wheel to the power output of straight-wing vertical axis wind turbine is larger, and improvement of wind turbine power performance is relatively significant while the distance is0.02m.3) It’s more obvious to improve power coefficient while the diameter of frustum-shaped equipment is equal with the diameter of wind wheel; Promotion effect is weaken while the diameter of frustum-shaped equipment is greater than the diameter of wind wheel; The power coefficient is reduced while the diameter of frustum-shaped equipment is less than the diameter of wind wheel.4) It’s more useful to improve power coefficient while wind speed is6m/s and angle of frustum-shaped equipment installed is20degree, as well as wind speed is lOm/s and angle of frustum-shaped equipment installed is30degree.Addition to the above contents, wind tunnel experiments concerning on the influence of power coefficient to straight-wing vertical axis wind turbine based on number of blade and airfoil of blade were also conducted. NACA0018(Symmetrical) and NACA7715(Unsymmetrical) were selected by the test. The number of blades is two, three and four, wind speed is6m/s and10m/s. The following is some conclusions:1) In the case of other structural parameters, the more number of blades, the sooner maximum power coefficient of wind turbine is got, the larger wind turbine power coefficient, and the power coefficient of two blades is less than three blades. Overall, the output performance of the4blades is best.2) The influence of airfoil to output power of straight-wing vertical axis wind turbine is greater, at low speed, the performance of wind turbine output of NACA0018is relatively better; however, at top speed, the performance of wind turbine output of NACA7715is relatively better.The feasibility of the application on the direction of vertical axis wind turbine has been verified through the test. At certain extent, it has ascertained the impact of structural parameters of wind gathering equipment on wind turbine output power. This study has provided the experimental basis to development of wind energy utilization of frustum-shaped wind gathering equipment and it also supplies a new thinking to straight-wing vertical axis wind turbine. The research on structural parameters of the straight-wing vertical wind turbine provides a reference for the design and development of wind turbine.