Advanced High-Lift Leading-Edge (AHLLE) Technologies for Laminar Wings

This is the Northrop Grumman final report for the Advanced High-Lift Leading-Edge
Technologies for Laminar Wings conceptual design and demonstration program performed for
the National Aeronautics and Space Administration Langley Research Center. Northrop
Grumman conducted conceptual aerodynamic CFD and QFD analysis to downselect two
leading-edge concepts for high lift. The effort included aerodynamic analysis to examine
instrumentation placement and propulsion analysis to design internal cavity geometry of the
high-pressure blown slot configurations. A wind tunnel model design created a 7-foot span
model of the complex configuration. A wind tunnel test plan, which included baseline, deflected
trailing-edge, blown deflected trailing-edge, blown leading-edge, morphed leading-edge, and
blown/morphed leading-edge airfoil configurations was developed. As a result of this program
approach, a successful demonstration of high-lift leading-edge technology was reached, and the target goals for improved lift were exceeded by 30% with a maximum section lift coefficient (Cl) of 5.2. Incremental lift coefficient (DCl) of 3.5 and 3.1 was achieved on the two laminar
compatible airfoil configurations (at cruise). Our high-lift design yielded a massive 94% lift
improvement over conventional high-lift Krueger flap configurations while providing laminar
flow capability on the cruise configuration.