1. meter measurements at Lockheect18for the same CC airfoil as in Figures 7-9 showed mean velocities which confirmed the CFD results above. Again, jet flow turning to a separation point/stagnation streamline approximately 130-145° from the slot was seen, Figure 10. Experimental investigations by this . author19 of a very similar generic airfoil, Figure II, used surface static pressure, static pressure across the jet and a rotatable hot-film shear stress probe to measure the actual separation point location (where shear stress= 0) as a function of blowing and slot height. As Figure 12 shows, jet turning as high as 170-175° was measured. At a constant Cµ, greater turning occurred with a smaller slot height because the resultant jet velocity and entrainment are higher as jet area reduces. Figure 13 shows that this greater velocity and jet turning clearly results in generation of higher CJ, where values nearing 9 are possible at a = 0° (although tunnel flow impingement occurs here). Figure 14presents associated static pressure distributions on the airfoil. These analytical and experimental data confirm the effectiveness of blowing to greatly deflect the entire flowfield and then strongly increase the circulation and lift on these very generic airfoils, to the point that very high lift is produced without wing flaps and slats and at 0° angle of attack. Some additional information on CC airfoils is provided in Reference 20.
2. Circulation Control Wing fCCW): This high-lift capahility independent of angle of attack which was demonstrated by the CC Rotor airfoils led to the application of CC as a simplified very-high-lift device for STOL aircraft. The airfoil in Figure I is representative of this simplified pneumatic concept, where both the mechanical trailing edge flap and the leading edge flap or slat have been replaced with non-moving pneumatic systems. Primarydevelopment of the concept took place in conjunction with CC Rotor development efforts at the Navy's DTNSRoc 12,16,26,27,28,29,30 in the time frame of late 1960sto early 1980s. Initially, the concept wasmodeledasasmalladd-ondevice 28that would convert the wing flap's sharp training edge into the round CC Wing (Figure 19),which was tested at DTNSRDC inspecialized 2-D high-lift test facilities 6. Compared to results from a family of