Computation And Analyses On The Aerodynamic Performance Of The Special Airfoils For Wind Turbine

On the basis of analysis about the status of the development of wind power andthe aerodynamic characteristics of the airfoils at home and abroad, the aerodynamiccharacteristics of some typical airfoils are calculated in this paper. The aerodynamiccharacteristics date of DU95-W-180with a clean and rough leading edge is obtainedby Fluent software, that compared to the experimental data, then the effectiveness ofthe2-D numerical simulation method is verified in certain conditions. The effect ofairfoil aerodynamic characteristic is studied up on radius of leading edge throughDU95-W-180and S810, tail edge roughness through FFA-W3-211, get somesignificant conclusion. The Detached Eddy Simulation is chosen to calculateaerodynamic performance of FFA-W3-241airfoil in a larger scope of angle of attack,the calculation results be compared to the experimental data, then the effectivenessof the3-D numerical simulation method is verified in stall developing region, theaerodynamic performance of the airfoil in roughness condition is predicted by the3-D numerical simulation method.The calculation results show that the roughness sensitivity of airfoils with asmall radius leading-edge is lower than that with a bigger one under a certainReynolds number and a fixed attack angle range when the thickness are equal.Improving the roughness of under surface close to the trailing edge can effectivelyimprove the lift coefficient, and the drag coefficient also be increased, but thelift-drag ratio is better. The thickness of the rough region has a optimal value and thewidth has a optimal and a threshold value. For the clean airfoil, with the Reynoldsnumber increasing, the lift coefficient increased and the drag coefficient decreased,so the lift-drag ratio increased. For the airfoil with a rough trailing edge, the liftcoefficient increased when the Reynolds number increased, but the drag coefficientdecreased first and then increased, the lift-drag ratio increased first and thendecreased. The calculation results show that the DES is suitable for the numericalsimulation on the aerodynamic performance of special airfoil for wind turbine inlinear region and stall developing region because of the calculative accuracy is good,the method also can be used to do qualitative analysis in fully stall region. Theleading edge roughness has a significant effect on the performance of FFA-W3-241airfoil, the maximal lift coefficient is reduced by27.8%and the stall process is moderatebecause of the increase of leading edge roughness; the airfoil is not sensitive to the leading edge roughness in linear region and fully stall region, however, it is sensitive in stalldevelopment region. In certain working conditions, when a Gurney flap be fixed onthe trailing edge with90°angle, the lift coefficient increased and the dragcoefficient increased too, the lift-drag ratio decreased in linear region, but increased install development region.