Mathematical Modelling of Vertical-Axis Wind Turbines Rotors Aerodynamics

Abstract

Numerical modeling of unsteady turbulent separated flows of incompressible fluid around vertical axis wind turbines (VAWT) with Darrieus and Savonius rotors was performed on the basis of the Reynolds-averaged Navier-Stokes equations, closed by the SpalartAllmaras turbulence model. The numerical solution was obtained using original homemade program code that implements an implicit finite volume algorithm based on the artificial compressibility method. Verification of developed CFD code has been carried out by simulation of several typical testing problems, namely: laminar and turbulent flow around steady and unsteady cylinder, subcritical and supercritical flow around steady and oscillating NACA 4412, NACA 0015 airfoils, aerodynamics of the turbulent flow around a 30P30N multi-element airfoil in cruise, takeoff and landing configurations, turbulent flow around tractor-trailer. The results of Darrieus and Savonius rotors simulation, physical and computational experiments with different number and geometry of blades are presented in the form of detailed flow visualization and reconstruction for two- and three-blade Darrieus rotor. The analysis of flow field near rotors was carried out and the main stages of vortex development were identified and analyzed. The results of three series of computational experiments on aerodynamic of two and three-bucket Savonius rotor were obtained, presented and discussed.