Understanding the flow behavior around Krueger flaps through the means of CFD simulations

Abstract This study aims to establish the feasibility of Krueger flaps acting as high lift devices on a natural laminar wing aircraft configuration. It is part of the German funded project ‘ULTIMATE’, aiming an aircraft wing design providing fuel savings up to 10% as compared to aircrafts today at the next short to medium range aircraft expected to enter the market in 2030. The current paper aims to outline the status of implementing Krueger flaps as leading edge high-lift system, arranged in distributed manner and the ability to achieve handling quality requirements in high-lift configuration, and taking into consideration failure cases, which allows compact kinematic and system designs fitting into the restricted space of the aerodynamic profile. The current work focuses on the evaluation of the achieved low-speed performance by Computational Fluid Dynamics as well as first insights into critical failure cases with Krueger flaps jammed in unfavorable positions.