Airfoil analysis for horizontal axis wind turbines

Abstract

A numerical algorithm has been developed for two dimensional rotating and non-rotating airfoil cross-sections. The steady Euler equations in the rotational plane with viscous boundary layer correction have been used for the analysis. The effects of boundary layers and wakes on the inviscid main stream flow are modeled by the displacement thickness concept. Both laminar and turbulent boundary layer thickness growth over the airfoil can be modeled. The transition point is input to the solution. The non-linear Euler-boundary layer system of equation is in integral conservative form and allows for the correct treatment of shock waves. The system is first linearized and then solved implicitly by a Newton-Raphson technique. The RAE 2822 airfoil has been used as a test case and good agreement have been obtained for the pressure coefficient and the boundary layer thickness distributions. The solver has also been successfully used in calculating the flow around a FFA-W1-242 horizontal axis wind turbine airfoil.