Numerical and Experimental Comparative Analysis of Synthetic Jet-based Wingtip Vortex Control

This study presents a combined numerical–experimental investigation of synthetic jet-based active control of wingtip vortices, with the aim of assessing the predictive capability of an unsteady Reynolds-averaged Navier–Stokes framework against Stereoscopic Particle Image Velocimetry measurements. The main novelty of the work lies in the validation of URANS simulations as a computationally affordable and first-order numerical tool for reproducing experimentally investigated actively controlled wingtip vortices under synthetic jet actuation, evaluating the ability of the numerical framework to capture both the mean and phase-averaged components of the actuation. The performed analyses consider both baseline (jet-off) and controlled (jet-on) configurations at a fixed momentum coefficient C μ = 0.2 % and two dimensionless frequencies, f + = 0.071 and f + = 0.55 . Regarding the baseline case, the simulations accurately reproduce the overall vortex roll-up and capture the vortex trajectory well in the near field, while increasing discrepancies arise downstream due to enhanced numerical diffusion and the intrinsic limitations of eddy-viscosity turbulence models. Under actuation conditions, the time-averaged results indicate a weakening and diffusion of the primary vortex. Both forcing frequencies promote the formation of a co-rotating jet-induced vortex, with the higher frequency yielding a more distributed attenuation. A quantitative comparison of the geometrical characteristics of the vortex core, based on an elliptical Gaussian fitting model, shows that numerical simulations capture the main trends in vortex growth and vorticity peak reduction, although vortex circulation and core diffusion are generally overestimated. Phase-locked analyses further demonstrate that the numerical model reproduces the main periodic modulation of the vortex strength induced by the synthetic jet, particularly during the blowing phase. Overall, the results of the study confirm that present numerical simulations provide a reliable first-order tool for assessing synthetic-jet control of wingtip vortices, while highlighting the need for improved wake resolution and higher-fidelity approaches to achieve fully quantitative agreement.