The automatic optimization method was applied to 3D aerodynamic design of a high bypass ratio fan blade. A genetic algorithm was used as numerical optimization method

and multiCPU parallel optimization was realized by using network communication protocol to greatly shorten the optimization time. The fan blade profiles

stack line

the flow passage in meridian plane

installation angle and chord length were set as design variables. The parameterization method based on modifications to these design variables was combined with the range limit of the design variables in the genetic algorithm

and it controlled and rationalized the individuals generated in optimization process.Dentons viscous volume force method was applied to flow field calculation of the fans

decreasing the calculation time and further reducing the optimization time. The optimization goal was set to improve the fan efficiency and keep total pressure ratio and mass flow rate unchanged at the design point

and the optimized fans performance at offdesign points was checked. The original fan was optimized in two steps

in which the design parameters were adjusted according to aerodynamic characteristics of the fan to be optimized. The final optimized fans efficiency increased from 09463 to 09560

and stability margin increased from 112% to 219%. Mach number of shock wave at blade tip section of the final optimized fan decreased slightly

and the shock wave leaned to the blade passages. Therefore

loss of the shock wave and its effect on boundary layer decreasd

and the stability margin increased.