MULTIPOINT INVERSE AIRFOIL DESIGN METHOD FOR SLOT-SUCTION AIRFOILS

Owing to a renewed interest in advanced-concept transport aircraft wit h active boundary-layer control (suction and/or blowing), a generalize d multipoint method for the inverse design of airfoils with slot sucti on in incompressible potential dow is presented. The results predicted by theory show good agreement with experiment. Such a design tool cou ld be used interactively to perform rapid trade studies to examine the potential payoff for boundary layer control as applied to the advance d-concept wings, The method, which is based on conformal mapping, draw s on the theory first published by Eppler (Airfoil Design and Data, Sp ringer-Verlag, New York, 1990) and extended by Selig and Maughmer (''A Multipoint Inverse Airfoil Design Method Based on Conformal Mapping,' ' AIAA Journal, Vol. 30, No, 5, 1992, pp. 1162-1170), The theory predi cts an increased lift coefficient and a nonzero value for the Inviscid drag coefficient as a result of the slot suction, a price to be paid for the increased lift. The theory also shows that this nonzero value of the inviscid drag coefficient is exactly equal to twice the suction coefficient Two examples are discussed to illustrate the method and t he corresponding change in the aerodynamic characteristics of the airf oils as a result of slot suction.