Research progress on laminar separation bubble dynamics and aerodynamic optimization of low-Reynolds-number airfoils

Abstract

This review examines the research progress on flow mechanisms and aerodynamic optimization of airfoils under low-Reynolds-number conditions, with emphasis on the formation and evolution of laminar separation bubbles and their effects on aerodynamic performance. Based on experimental studies, numerical simulations, and optimization design research, the characteristics of the separation, transition, and reattachment processes are analyzed, as well as the controlling effects of laminar separation bubbles on typical aerodynamic responses such as lift, drag, stall, and static hysteresis under different operating conditions. On this basis, the main technical approaches for low-Reynolds-number airfoil optimization are summarized, including geometry design based on pressure distribution regulation, numerical optimization considering transition effects, passive and active flow control, and data-driven optimization methods. Finally, the challenges faced by current research in transition prediction, multicondition robustness, and physics-constrained modeling are discussed. Overall, the research framework centered on laminar separation bubble control provides a unified physical understanding and design strategy for improving the
performance of low-Reynolds-number airfoils.