Aerodynamic optimization design of micro-helicopter rotor airfoil based on genetic algorithm

Micro helicopters have essential application value in military and civil fields, but critical challenges persist in endurance limitations and operational range constraints. In this paper, the aerodynamic performance optimization of rotor airfoil of micro helicopter under low Reynolds number conditions is investigated, and a multi-stage collaborative optimization method is proposed. The methodology comprises three primary phases: First, a baseline airfoil configuration was synthesized through aerodynamic fusion of the NACA0012 and S1223 airfoil profiles, balancing high lift-to-drag characteristics with longitudinal stability. Subsequently, a multi-objective optimization framework integrating Bessel-curve parameterization and genetic algorithm (GA) optimization was developed for airfoil geometry optimization. Finally, computational fluid dynamics (CFD) simulations were employed to varify aerodynamic improvements and elucidate underlying flow mechanisms. Numerical results demonstrate that the optimized airfoil achieves a 33% improvement in lift-to-drag ratio compared to the baseline configuration under typical operational conditions (Re=6×104, AOA=10°). Flow field analysis reveals that this enhancement primarily originates from optimizing the location of flow separation points and improved location and size of laminar flow separation bubbles. The proposed methodology provides a systematic approach for micro-rotorcraft performance augmentation, offering valuable insights for low Reynolds number aerodynamic design optimization.