Challenges Quantifying the Transonic Characteristics of Swept Tuberculated Leading Edge Wings

This paper documents a better means to characterize the transonic characteristics of tuberculated leading-edge airfoils. Tubercules, high-spatial frequency variations in leading-edge sweep, gained the attention of the aeronautics community and may serve as an effective passive flow-control mechanism to improve the CLmax of wings. Originally inspired by humpback whale fins, computational and wind tunnel studies indicate significant benefits in the post-stall regime. At the same time, little has been discussed in terms of how they impact shock formation. This paper demonstrates the fundamental challenges quantifying the transonic characteristics of “quasi-2-D” tuberculated leading-edge airfoils. Our CFD studies show that a “quasi-2-D” approach can be used to assess low-speed characteristics, works poorly to characterize their transonic behavior.