Analysis of the experimental and computational flow characteristics with respect to the augmented lift phenomenon caused by blade rotation

Abstract

This article focuses on the augmented lift phenomenon as a result of blade rotation in the steady state non-yawed condition. In the investigations a full Navier Stokes code FLUENT is used instead of engineering models. The calculations are compared with the measurements of the Unsteady Aerodynamic Experiment at the NASA Ames wind tunnel at wind speeds between 8m/s and 15m/s in steps of 1m/s. The computations show good agreement for the pressure distributions for almost all five segments at wind speeds below 10m/s, only large deviations occur at segment r/R= 0.47. Beyond 10m/s deviations with the experiment increase but still, apart from the inboard r/R= 0.30 segment and occasionally the r/R= 0.47 location, the results are surprisingly good. Large separated areas and cross flows dominate the flow on the suction side as can be distracted from the calculated limited streamlines. Integration to the normal force coefficient showed that the trends of the experimental data are followed reasonably well for each span section. The presence of augmented lift and stall delay was confirmed for the span sections at r/R= 0.30 and r/R= 0.47. © 2007 IOP Publishing Ltd.