Computational study of horizontal axis wind turbines

A hybrid Navier-Stokes potential flow methodology for modeling three-dimens ional unsteady viscous flow over horizontal axis wind turbine configuration s is presented. In this approach, the costly viscous flow equations are sol ved only in a small viscous flow region surrounding the rotor. The rest of the flow field is modeled using a potential flow methodology. The tip vorti ces are modeled using a free wake approach, which allows the vortices to de form and interact with each other. Sample results are presented for two rot or configurations tested by the National Renewable Energy Laboratory. Compa risons with experimental data, full Navier-Stokes simulations and blade ele ment momentum theory are given to establish the efficiency and accuracy of the present scheme.