Aerodynamic Optimization Design Of A Highly-loaded Two-Stage Fan Stator With A Small Bypass Ratio

Increasing fan load can reduce fan series,which is of great significance to the design of compressor fan.The main task of this paper is to carry out the optimization design of a highly-loaded two-stage fan to improve the aerodynamic performance of it.The calculation analysis of the two and half stage fan found that,the pressure ratio of the first stage fan is greater than the second stage fan,rectification of the second stage stator is greater than the first stage stator.This paper adopts parallel genetic algorithm to optimize the two-stage fan stator.Because the first stage fan stator has much constraint,the optimization design effect is not obvious.For the second stage stator optimization design,through changing the bowl and sweep of stator,the total pressure recovery coefficient of the stator increased by 0.2 percentage points,total efficiency of two-stage fan increased by 0.1 percentage points.To design stator,a quasi-three-dimensional method and optimization design in three-dimensional environment were adopted.Through S2 stream surface calculation,the parameters distribution along the span and the parameters of were determined.The initial profiles design includes profiles of 10%,50% and 90% span design.A three-dimensional blade was obtained through stacking three sections along the span and reduce the loss of the blade through optimization design of profiles.Through the calculation of the fan,the highest efficiency of the fan increased by 0.50 percentage points,and the total pressure recovery of the stator increased from 0.9720 to 0.9765,and the tangential flow angle of the stator was nearly 0.The optimization design effect of the stator blade was not obvious because the effect of the rectification declined,due to modifying the profile.In the multi-stage fan design,design a stator with a low loss and air flow turning more for intermediate stage stator,and carry out a numerical simulationfor the fan stage to prove that the scheme has certain feasibility.Design a stator with a larger flow turning angle,according to the thinking.This stator design process is similar,through optimization design of profiles,the total pressure recovery coefficient increased to 0.9760.The optimization design of the stator,the channel changed and the fan efficiency increased by 0.2 percentage points,but this is mainly due to the rotor performance and the stator loss is not reduced.