MULTIELEMENT AIRFOIL PERFORMANCE DUE TO REYNOLDS AND MACH NUMBER VARIATIONS

Experimental studies have been conducted to assess Reynolds and Mach n umber effects on a supercritical multielement airfoil. The airfoil is representative of the stall-critical station of an advanced transport design. The experimental work was conducted as part of a cooperative p rogram between the Douglas Aircraft Company and the NASA Langley Resea rch Center to improve current knowledge of high-lift flows and to deve lop a validation data base with practical geometries/conditions for em erging computational methods. This article describes results obtained for both landing and takeoff multielement airfoils (four- and three-el ement configurations) for a variety of Mach/Reynolds number combinatio ns up to flight conditions. Effects on maximum lift are considered for the landing configurations, and effects on both lift and drag are rep orted for the takeoff geometry. The present test results revealed cons iderable maximum lift effects on the three-element landing configurati on for Reynolds number variations, and significant Mach number effects on the four-element airfoil.