Aft-swept Blade Aerodynamic Shape Design And Numerical Simulation Of Flow Field

Compared to conventional wind turbine blade, aft-swept blade can improve itsaerodynamic appearance and wind energy utilization, and reduce the energy loss and bladestress, and extend the life of the blade downstream components because its aerodynamicshape can change inflow state. So it is important to study its aerodynamic shape andnumerical simulation of flow field.Aiming to increase the average output power of wind turbine, this paper uses the analogymethod to apply the cubic spline curve on swept fan blade stacking line to the aft-swept blade.Selecting a conventional parallel side blade as the prototype, the50%after-segment along theblade length is deformed by the cubic spline curve to act as the aerodynamic shape of aft-swept.The3D models of aft-swept blade and parallel side blade are created respectively using UG.After calculating the discrete points exhibition of cross-section on space coordinates, import thecoordinate file to UG software to establish the smooth three-dimensional model. The rotatingand the stationary flow fields are created by Gambit software, then the flow fields are meshedand the reasonable physical boundary conditions are set. Importing the mesh files to Fluentsoftware to transform polyhedral ones, and setting simulation algorithm, interpolation type, andbasic parameters of the physical model，then the flow field is simulated. Moreover, according tothe specific case of divergence control equation，setup parameters are modified, and then theiteration are recalculated repeatedly until convergence. The effective torque wind turbine isgained. The average powers and annual power generation capacities of the two different windturbines under Weibull distribution are calculated and compared.The results show that aft-swept wind turbine increases the power generation by4.13%compared to prototype one，which reflects the analogy design could provide a reference ideafor the aerodynamic shape design of aft-swept blade in wind turbine in theory. However itshould be further optimized to improve power generation with the other degree of free thatairfoil, chord, twist angle of the aft-swept blade.