Experimental and computational aerodynamic investigations of very thick wind turbine airfoils

Abstract

The aerodynamic performance of two very thick wind turbine airfoils, DU00-W-401 and CAS-W1-450, is examined by experimental and computational methods at a Reynolds number of 1 × 106. The measurements were carried out in a wind tunnel with a cross-sectional dimension of 1.5 m × 1.5 m and a length of 2.5 m. The results are compared with predictions from Reynolds-averaged Navier-Stokes (RANS) simulation with a k-ω turbulence model and a transition model. To eliminate the unstable effect, three runs of measurements were conducted and then the results were averaged. The lift performance of DU00-W-401 is in good agreement with a previous research result, showing the experimental method is reliable. RANS well predicts the lift performance at the linear region on the lift curve, but tends to underestimate the drag and overestimate the lift in post-stall condition. The pressure drag taking a large proportion to the total drag results in a high drag coefficient for the very thick wind turbine airfoil. A three-dimensional characteristic is observed in the experiments by comparing surface pressure at different spanwise positions.