Experimental/Analytical Investigation into the Performance of a 20-Percent Thick, 8.5-Percent Cambered, Circulation Controlled Airfoil.

摘要

This study was conducted to investigate the effect of two tangentially blown slots on the performance of a 20-percent thick, 8.5-percent cambered elliptical airfoil. Lift, drag, and moment coefficients were obtained at a test Reynolds number of 9.5 x 100,000 for secondary slot locations of 73.5 and 83.5 deg. Results show that the use of two tangentially blown slots enables the generation of higher lift coefficients at lower blowing rates. This feature enables the test airfoil to equal the performance of single slotted blown airfoils at lower blowing rates therefore reducing the parasitic losses and resulting in higher lift/drag ratios. A limited study of the ability of the (TRACON) program to predict circulation controlled airfoil performance was conducted. The program failed to provide accurate predictions for the pressure distribution or force coefficients for the airfoil configuration of this study. This study also found that using different geometry smoothing techniques in the region of the slot resulted in large variations in TRACON's performance predictions.