Effect of Spanwise Blowing on the Aerodynamic Characteristics of the F-5E

A 1/lO-scaIe F-5E was tested to investigate the spanwise blowing concept to provide improved aerodynamic characteristics with primary emphasis on high angle-of-attack performance and stability. Test data were obtained in the Northrop 7 X 10-ft low-speed facility at a freestream Mach number of 0.18 for a range of model angle of attack, sideslip, jet momentum coefficient, and leading- and trailing-edge flap deflection angles. Spanwise blowing on the 32 deg-swept wing from the wing/leading-edge extension (LEX) junction at a nozzle sweep angle of 55 deg resulted in LEX and wing leading-edge vortex enhancement and large vortex-induced lift increments and drag polar improvements at the higher angles of attack. Spanwise blowing improved the lateral/directional characteristics by delaying wing stall and maintaining vertical tail effectiveness to higher angles of attack. Deflecting the leading- and trailing-edge flaps down to 24 deg and 20 deg, respectively, delayed to higher model attitudes the more beneficial effects of blowing. Blowing reduces the specific excess power available for maneuvering the F-5E.