Numerical Simulation And Optimization Research On Flow Stiffness Of Composite Energy Trapping Column Of Vaneless Wind Turbine

The energy capture column of vaneless wind turbine generates vortex-induced oscillation in the wind field to obtain wind energy.The energy capture system itself has certain stiffness property,which has certain influence on the energy absorption efficiency of the energy capture column in the change of flow field pressure.In this paper,the composite carbon fiber and epoxy glass fiber are used to lay up,and the effects of different laying order,different laying angles,different thicknesses and different models on all-directional stiffness performance of the energy harvesting column shell are discussed.Then,the lightweight of the energy harvesting column shell is realized through optimization analysis.The research work of this paper is as follows:(1)Using the control variable method,the influence of different layers,layers sequence and layers angle on the numerical analysis of the static stiffness of the flexible shell of the energy harvesting column of vaneless wind turbine is studied.Orthotropic composite carbon fiber and epoxy glass fiber have high stiffness and are suitable for laying energy-harvesting columns of laminated plates.With the increase of the number of layers,the main Poisson’s ratio decreases obviously and the deformation resistance of the whole shell is greatly enhanced.The ply angle gradient is 90,and the values of tensile stiffness,compressive stiffness and bending static stiffness are the maximum.The optimal stacking modes of hyperbolic,parabolic and conical energy-harvesting column shells have the same stacking angles.(2)Under the condition that the angle gradient of the laminated plate shell is 90 and the number of laminated layers is five,three different models of energy capture columns are studied to change the shell shape structure,and the numerical influence of the flow stiffness under the fluid-solid coupling effect is discussed.Through numerical analysis,the three-layer carbon fiber antisymmetric laminated plate energy harvesting column shell has the best performance parameters in all directions.Under the specific flow field,when the energy capture system is subjected to fluid-solid coupling,the wind speed increases continuously,and the flow stiffness performance becomes stronger.When the wind speed is 8m/s,the flow stiffness of hyperbolic and parabolic energy capture columns is the highest.Three different flow stiffness and dynamic stiffness values are larger than bending stiffness values,while the flow stiffness values of hyperbolic energy harvesting column shell at the same wind speed are larger than those of the other two energy harvesting columns.(3)According to the best shell model,the target parameters are thickness and wind speed,and the effects of the maximum deformation,maximum equivalent stress and mass response of three different shells are studied.The response surface analysis of energy capture column shell is carried out by Optimization module.The target parameters of energy capture column structure,such as maximum elastic deformation,maximum equivalent stress of shell,shell quality judgment coefficient,are close to 1,and the root mean square error is close to 0,while the optimal values of relative average absolute error and relative maximum absolute error are 0.The shell thickness parameter plays a leading role in the response surface,and the sensitivity analysis shows that the shell quality has the greatest influence on its model.The shell optimization results of hyperbolic and parabolic energy capture columns are better.In this paper,the numerical simulation of the flow stiffness around the composite energy capture column of vaneless wind turbine is optimized,which can provide guidance for the structural parameters of the energy capture column of vaneless wind turbine.