Study Of The Effect Of Vortex Shedding On A 5kw H-type Vertical Axis Wind Turbine

Wind power has become increasingly the most promising way of clean power generation in the field of new energy because of its distinguishing features of clean, renewable and its large-scale application technology maturing. The vertical axis wind turbines(VAWTs) do not need to adjust the direction of the wind and generators, gear boxes and other equipments can be placed on the ground, etc. All of these make VATWs become the development trend of new type and high efficient wind turbines. But the flow structure of VAWT is complex. It is a typical large separation unsteady flow. Airflow passing through tower or rotor shaft will generate periodic vortex shedding. Vortex shedding will cause wind turbine vibration and deformation and also makes large impact on the mechanical properties of the structure. Therefore, it is important to study the influence of vortex shedding on the VAWT.The paper takes a 5 kW H-VAWT as the object of study. Computational fluid dynamics (CFD) method is mainly used to analyze vortex shedding. ANSYS is also applied to analyze the impact of vortex shedding on the structure. The main contents of research are as follows:The 5 kW H-VAWT parameters are designed according to the basic theory of wind turbine. Stress analysis was carried out on the parts, and ANSYS finite element method is used to do static strength check.For the problem of vortex shedding, GAMBIT, the pretreatment software of CFD, is used to establish two-dimensional wind turbine model. SST turbulence model is chose to solve the incompressible viscous fluid Navier-Stokes equations. The various parameters of wind field are got by the use of fluid dynamics software FLUENT at different speeds. Analysis shows that the periodic vortex shedding force can induce vortex-induced resonance within the scope of the wind machine normal operation. Vibration status of the structure of vortex-induced resonance is got.The effect of vortex shedding of the rotor on the utilization of wind power is studied by the use of CFD numerical simulation analysis. The rule of the change of diameter of rotor on the effect of wind energy utilization is got. The result of flow field analysis shows that there is certain strength of vortex shedding striking the blade surface. The effect of vortex shedding of rotor on the blade surface pressure change and the change of stress and strain are obtained by the use of FLUENT and ANSYS analysis. This provides certain reference on the analysis of blade fatigue life.To sum up, through the combination of theoretical analysis and numerical calculation, the effect of the vortex shedding on the vertical axis wind turbine performance is studied. The influence of vortex shedding on the wind turbine rotor, tower and leaf structure mechanics performance is got. The research offers contribute to the design and standard specification of H-VAWT. Therefore, the research of this paper has important theoretical significance and engineering application value.