Aerodynamic shape optimization design of high-speed coaxial counter-rotating propeller blades based on Bayesian optimization method

This study establishes a Bayesian optimization-based aerodynamic shape optimization framework for high-speed coaxial contra-rotating propeller blades, aiming to enhance aerodynamic efficiency under cruise conditions. Within this framework, the multiple reference frame (MRF) method coupled with Reynolds-averaged Navier-Stokes (RANS) equations is adopted to accurately evaluate three critical factors affecting aerodynamic characteristics: 1) blade-to-blade aerodynamic interaction, 2) air compressibility at high rotational speeds, and 3) complex blade geometry effects. A Kriging surrogate model is developed to map the relationships between design parameters and aerodynamic responses, with a composite infill criterion implemented to accelerate convergence. Aerodynamic-structural integrated parameterization is implemented, independently defining chord length, twist distribution, and sweep configuration for both forward and aft propellers. The final optimized configuration demonstrates a comprehensive aerodynamic efficiency of 0.8413 when accounting for spinner and rotating shaft effects, representing a 1.53% improvement over the baseline design. Load distribution analysis reveals distinct peak loading positions at 0.75R (forward propeller) and 0.7R (aft propeller) respectively.