The Analysis Of Fluid-structure Interaction On Cantilever Blade Of Vertical Axis Tidal Current Turbine

With the gradual depletion of fossil fuels and environmental degradation,ocean renewable energy has gradually attracted worldwide attention.As a kind of marine energy,tidal current energy has become a new hot spot in the field of ocean engineering and energy.As one of the major means to get the tidal current energy,the turbine is gradually moving towards large-scale,which will inevitably bring a series of researches about structural deformation and even destruction.Based on the theory of viscous fluid mechanics and structural finite element,the hydrodynamic performance and structure performance of the cantilever blade of vertical axis tidal current impeller were studied by using the method of unidirectional and bi-directional fluid structural interaction.And based on the theory of composites mechanics,the internal structure and the external skin of the blade were simply designed.Through researches in this paper,it provides a reference for the prediction of the performance of the vertical axis hydraulic turbine and the design of the blade.Main studies in this paper are as follows.Firstly,based on the CFD numerical simulation method,the hydrodynamic performance of cantilever vertical axis turbine impeller is analyzed and calculated.And a series of laws of hydrodynamic performance under different speed ratio are obtained.Secondly,based upon the finite element theory,the static strength,transient dynamics,modal and fatigue analysis of the solid and homogeneous blade were carried out.And some structural strength data of the balde were summarized,both in the air and in the water.Thirdly,combined with CFD numerical calculation and structural finite element theory,the relevant theory of unidirectional and bi-directional fluid-solid coupling methods were analyzed in this paper.Then,through contrastive analysis,the merits and drawbacks of them in the prediction of the vertical axis tidal current impeller's performance were discussed.After the two-way FSI analysis of the blade,the effects of material properties and the speed ratio on the hydrodynamic and structural performance of the blade were investigated in this paper.After that,the deformation and stress variation of the blade during one cycle of operation were studied in detail for some speed ratio and materials.Finally,based on the data of fluid-solid coupling and the theory of mechanics of composites,the internal structure of the blade and the way of laying the composite material were designed.Then,some futher calculations and analysis were taken to verify their impact on the hydrodynamic and structural performance of the new blade.So that,we can design a cantilever blade with excellent hydrodynamic performance and reliable structural strength for the vertical axis tidal current impeller.