Numerical Investigations of Spanwise-Varied Unsteady Coanda Actuation on High-Lift Configuration

Abstract

The present study investigates possible lift gains generated by spanwise-varied blowing on a high-lift configuration equipped with a droop nose and a Coanda flap. Two types of numerical simulations are performed and compared: unsteady Reynolds-averaged Navier–Stokes simulations and improved delayed detached-eddy simulations with algebraic sensors. The unsteady Reynolds-averaged Navier–Stokes simulations achieve the best actuation settings at an actuation amplitude of 25% of the jet slit height and an actuation frequency of . No relevant sensitivity is detected with regard to the phase shift of the actuated spanwise segments. In contrast, the algebraic improved delayed detached-eddy simulations results show clear sensitivity to actuation phase shift. The algebraic improved delayed detached-eddy scale-resolving simulations also exhibit different wake dynamics from those of unsteady Reynolds-averaged Navier–Stokes. Based on both the unsteady Reynolds-averaged Navier–Stokes and algebraic improved delayed detached-eddy simulations results, this study demonstrates the benefits that the superposition of a two-dimensional periodic actuation component (no phase shift between actuated segments) has on the lift. The benefits of three-dimensional segmented actuation remain unknown and await further research.