A Computational Investigation For The Flow Over A Blade Of Vertical Axis Turbine With Automatic Open And Close Blade

The flow over a blade of vertical axis turbine with automatic open and close blade was simulated by using Fluent software based on RANS equations and standard k-? model.The blade was composed of semi ellipse + circular streamline and Clark Y airfoil,so that,when it was closed,the minimum resistance was generated,and the maximum resistance was obtained when it was opened.In this way,it could produce greater torques.The calculation results showed that when the blade rotated from 0 to 90 degrees and 270 to 360 degrees,it had a trend to close and rotate anticlockwise.When it rotated from 90 to 270 degrees,it always had a trend to open and rotate clockwise.So that,the characteristics of the law about the blade opening and closing were suddenly changed.The results also showed that if two symmetrical blades were used to combine the turbine,it could realize self starting and maintain directional rotation.But the torques changed with rotation angles so that it could not rotate at uniform speed.Therefore,the turbine should be composed of several pairs of symmetrical blades.