Numerical and Experimental Study of Drag Characteristics of HLFC Airfoils in High Subsonic, High Reynolds Number Flows

Hybrid laminar flow control (HLFC) is one of the most practically promising aircraft drag reduction technologies. We have investigated both numerically and experimentally aerodynamic characteristics of HLFC airfoil and wing at high subsonic, high Reynolds number conditions. In this paper we report the result of a wind tunnel test on drag characteristics of two-dimensional HLFC airfoils with porous and slot suction approach under some adverse factors against laminar flow, and a numerical analysis of the wind tunnel data, which is based on the boundary layer calculation with new transition prediction method allowed for the adverse factors and the Squire-Young drag formula.