Design Of Horizontal Axis Wind Turbine Blade And Its Fluid Structure Interaction Simulation

This thesis aim to design a blade of a large scale wind turbine whose power is3MW.Procedure of blade geometry design and build up, structure type decision, laminate composite scheme creation and optimization were implemented. Our target is to combine theory with finite element analysis and work out an overall wind turbine blade design scheme.First of all, some material and theory are referred and design parameters are computed such as radius number of blade and tip speed ratio. Then after some comparison between Glauert theory and Wilson theory we adopted the latter as our blade geometry design theory. Some airfoil profiles are chosen including FFA-W3-301, NACA63-415etc. Some scaling is made to one of the profiles then came FFAWM-35and FFAW3-40which had proper chord height ratio to finish the design at the blade root. A program was written in Matlab to compute attack angle and other parameters, export the model of a blade in form of an ibl file with the program as well. Then3D model of blade was built in way of boundary blend by Pro/E. After that, model of blade was imported into ANSYS Workbench and further modifications were made, webs of blade were built inside and both fluid fields near blade and far from blade were model. Finally, both structural and fluidic finite element model in ANSYS and Fluent needed to carry on the two-way fluid structure interaction (FSI) simulation were built up by meshing.Then load case and boundary condition of blade were determined including the speed of wind and turbulence intensity and turbulence length scale, then number of sub-steps and step end time were set. Then ANSYS-Fluent coupling analysis was carried out with help of a new multi-field coupling assistant part System Coupling in AWB. Dynamic response of blade under aerodynamic loading were computed as first order computation, maximum positive pressure on blade surface is963.5Pa which is closed to the basic wind pressure, then we have the conclusion that the simulation result was reliable, and maximum deformation of blade was at time of0.4s whose result will be used to finish the subsequent design.. Researches on composite material lay up design theory applying on blade were done, route of composite lamination and internal forces were export from the above first order computation as design parameters. Then a program was written base on the laminate design theory, pressed thin shell buckling theory and the exported data from above to do the laminate composite lay up design, then the first order lay up scheme which is arbitrary angle lamination and variable-thickness was achieved.Eigen value computation was done base on the above first order lay up scheme which be taken as base of optimizations. Some adjustments of composites lamination scheme were made, then number of sub-steps were modified to200and step end time were modified to0.5s,then both first order lay up scheme and lay up scheme after optimization were used to do the above two-way fluid structure interaction simulation and eigen value computation. Finally, it came out that first order buckling coefficient raised from3.3298before optimization to4.2259after optimization, Tsai-Wu strength ratio raised from3.42to4.01, but weight of blade droped from16.71tons to15.99tons.The above work had a desirable outcome eventually, which gives some helpful information to overall design of wind turbine and blade design with help of two-way fluid structure simulation.