Comparison of Tip Vortex Noise for Squared and Rounded Tips

This paper investigates wingtip-generated noise using high-fidelity computational fluid dynamics coupled with aeroacoustic solvers. Two wingtip geometries—a rounded tip and a squared tip—are examined at both low and high angles of attack to assess their influence on vortex dynamics and resulting acoustic radiation. A key finding of this study is the discovery that the wingtip vortex induces trailing-edge vortex shedding (TE-VS) at the outboard span. The tip vortex modifies the local upwash near the trailing edge, triggering TE-VS even in regions where classical shedding would not occur. This enhanced TE-VS mechanism generates strong tonal radiation at the dominant peak frequencies for both geometries and angles of attack. For the squared tip, substantially higher broadband noise levels are observed compared with the rounded tip, driven by energetic side-edge secondary vortices and their interactions with the primary vortex system. In contrast, the rounded tip produces smoother vortex roll-up and weaker broadband content. The analysis further shows that turbulent boundary-layer trailing-edge noise can be important for the rounded tip, where tip-generated broadband noise is relatively weak, whereas it becomes less significant for the squared tip, whose strong vortex dynamics dominate the broadband spectrum. These findings highlight the critical role of wingtip geometry in shaping both tonal and broadband noise emissions.