Aerodynamic Performance Study On Hydrodynamics Characteristics Of Wind Turbine With Flexible Blades

In recent years, the fast growth of total energy consumption leads to the wind powerindustry develop rapidly and wind power installed capacity increases rapidly each year.At the same time, limited transmission capacity restrains consumption of wind power andthe problem of dropping wind power become serious. The development of distributedsmall wind power system can solve consumption problem. With setting up separatepower supply system, the problem of regional power shortage should be solved.A new type wind turbine which’s blades made of flexible material was designedbased on the bionics. Wind can alter the blades profile so that improving the distributionof flow field. The new type wind turbine has simple structure and needs lower start-upwind speed. It is removable. The flexible blade is key object in research project. The lawof blade curvature and attack angle effecting on flow field was found. The root cause wasalso found.Some experiments and numerical simulation have been accomplished. In order tofacilitate the experimental test, Flexible blade chain wheel was simplified for Arraycascade. Blade surface pressure testing experiments have been accomplished by multipoint synchronous pressure measurement technology. Thirty groups of lift coefficientwere contrasted and analysed. The best curvature is between curvature0.013and0.026,the best angle is between15degrees and25degrees. Numerical simulation model offlexible blade was setting up. Ultimately, the results show that best curvature is0.019andbest angle is20degrees.Flow field test experiments have been accomplished by PIV technology andnumerical simulation. Forty-two groups distribution of flow field were compared. Whenattack angle less than20degrees, boundary layer on suction surface keeps well stream.But when attack angle reaches30degrees, adverse pressure gradient on suction surfacewas increased rapidly so that boundary layer separates and vortexes were produced.Ultimately, the lift-to-drag ratio decreased. Moderate blade curvature can improve thestream. But excessive curvature can increase adverse pressure gradient rapidly on suctionsurface so that boundary layer separates and vortexes were produced. It is harmful foraerodynamic characteristics. vortex-shedding has periodicity and instability so that it can arouse strong perturbation and structural vibration.The law and the root cause of curvature and attack angle affecting on lift coefficientwas found. The best curvature and attack angle can be in favour of optimizing flexibleblade wind turbine.