Numerical Study for Active Flow Control on High-Lift Configurations by Oscillating Dropped-Hinge Flaps

Oscillating trailing-edge flaps have the potential to improve transport aircraft efficiency by leveraging dynamic lift effects, enabling larger flap deflection angles and higher average lift coefficients than traditional high-lift systems. This study presents a numerical investigation of a generic high-lift configuration, based on the NASA high-lift research airfoil, featuring a harmonically oscillating dropped-hinge flap. Numerical flow simulations are conducted on a block-structured grid using steady and unsteady Reynolds-averaged Navier-Stokes methods at landing flow conditions, and the numerical setup is validated against experimental data. Design parameters include mean flap deflection angle, oscillation frequency, and amplitude. A delay in flow separation and an increase in time-averaged lift coefficient are observed compared to a steady deployed flap, with these phenomena strongly dependent on the parameter space and further unsteady effects, such as vortex shedding. The gained insights contribute to evaluate how oscillating flaps drive lift enhancement, ultimately aiming to improve future high-lift systems. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2026.     «

Oscillating trailing-edge flaps have the potential to improve transport aircraft efficiency by leveraging dynamic lift effects, enabling larger flap deflection angles and higher average lift coefficients than traditional high-lift systems. This study presents a numerical investigation of a generic high-lift configuration, based on the NASA high-lift research airfoil, featuring a harmonically oscillating dropped-hinge flap. Numerical flow simulations are conducted on a block-structured grid using...     »

Funding text This research was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) in the framework of the project Active Flow Control through Oscillation of a Dropped-Hinge Flap (BR 1511/19-1). Special thanks are addressed to ANSYS for providing the flow simulation software. Furthermore, the authors gratefully acknowledge the Gauss Centre for Supercomputing e.V. (www.gauss-centre.eu) for funding this project by providing computing time on the GCS Supercomputer SuperMUC-NG at Leibniz Supercomputing Centre (www.lrz.de).     «

Funding text This research was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) in the framework of the project Active Flow Control through Oscillation of a Dropped-Hinge Flap (BR 1511/19-1). Special thanks are addressed to ANSYS for providing the flow simulation software. Furthermore, the authors gratefully acknowledge the Gauss Centre for Supercomputing e.V. (www.gauss-centre.eu) for funding this project by providing computing time on the GCS Supercomputer Super...     »