Research On Parameter Optimization For Variable Pitch Control Of Vertical Axis Wind Turbine

Wind energy is large-scale development because of the environment and energy issues of human society. Wind power is the principal form of wind energy. There are two kinds of wind turbine according to the type of rotating axis: HAWT (Horizontal Axis Wind Turbine) and VAWT (Vertical Axis Wind Turbine). Now the HAWT is more popular than VAWT. Over the last decade, the research and application of VAWT began to attract the attention, but the disadvantage of low power coefficient has always restricted its development. This thesis is in order to improve the VAWT's power coefficient.To improve the VAWT's power coefficient, this thesis uses variable pitch technology for VAWT. The pitch angle under different azimuth angle is optimized. By changing the pitch angle, the leaf in different positions can get the right angle of attack, and it can get larger rotational torque, thus its aerodynamic performance and power coefficient are improved.This thesis firstly introduces the basic theory of wind turbine design, and analyzes the theory of VAWT's variable pitch technology. Then basing on computational fluid dynamics(CFD) software Fluent, the VAWT's blade aerodynamic performance simulations are done, and the law of angle of attack on the blade performance is gotten. With the fixed pitch VAWT aerodynamic pdiefrffeorremnta npcitec hs iamnugllaetsi oanrse, gtoorttqeune. Bcuyr vaensa loyfz ain sgi nthgele V lAeaWf Tan'sd ttohreq uCep c u rλv ecsu rovfe as suinndgeler leaf, the thesis identifies the principle of the pitch angle optimization, obtains variable pitch curves of different tip speed ratio(TSR). Then the aerodynamic simulations of variable pitch VAWT are done, and its largest power coefficient is 0.495, comparing to a 32.4% raise with fixed pitch VAWT.In order to compare with the simulation results, the thesis designs, manufactures a VAWT prototype. At the same time the blade aerodynamic experiment is done, and the results are basically consistent with the simulation results.