This article is a U.S. Government work and is in the public domain in the U.S.A.
Development of engineering aerodynamics models using a viscous flow methodology on the NREL Phase VI rotor†
Article first published online: 22 JUL 2002
Copyright © 2002 John Wiley & Sons, Ltd.
Special Issue: Analysis and Modeling of the NREL Full-Scale Wind Tunnel Experiment
Volume 5, Issue 2-3, pages 171–183, April - September 2002
How to Cite
Xu, G. and Sankar, L. N. (2002), Development of engineering aerodynamics models using a viscous flow methodology on the NREL Phase VI rotor. Wind Energ., 5: 171–183. doi: 10.1002/we.73
- Issue published online: 22 JUL 2002
- Article first published online: 22 JUL 2002
- Manuscript Accepted: 4 MAY 2002
- Manuscript Revised: 26 APR 2002
- Manuscript Received: 26 NOV 2001
- National Renewable Energy Laboratory (NREL).
- tip loss model;
- stall delay model;
- computational fluid dynamics;
- hybrid method;
- Navier–Stokes equations;
- full potential equation
A numerical technique has been developed for efficiently simulating fully three-dimensional viscous fluid flow around horizontal axis wind turbines. In this approach the viscous region surrounding the blades is modelled using the 3D unsteady Navier–Stokes equations. The inviscid region away from the boundary layer and the wake is modelled using potential flow. The concentrated vortices that emanate from the blade tip are treated as piecewise straight line segments that are allowed to deform and convect at the local flow velocity. The Biot–Savart law is used to estimate the velocity field associated with these vortices. Calculations are presented under axial wind conditions for the NREL Phase VI rotor, a two-bladed rotor tested at the NASA Ames Research Center 80 ft × 120 ft wind tunnel. Good agreement with the measurements is found. The computations were verified against the experimental data and then used to develop improved engineering models for the loss of lift at the blade tip and for the delay in the stall angle at inboard locations. The procedure of developing improved aerodynamics models using validated CFD results as a guide is presented. The improved models are incorporated in a blade element momentum analysis to study the post-stall behaviour of a three-bladed rotor tested at NREL for further validation. Copyright © 2002 John Wiley & Sons, Ltd.