Numerical Study Of Curved/ Twisted/Swept Blade In Fan Retrofit Design

With the continuous improvement of the thrust-to-weight ratio,the requirements for the aerodynamic performance of the compressor components of the aviation turbine engine are also increasing.Compressors must achieve higher pressure ratios with fewer stages while maintaining high efficiency and sufficient surge margin.So it is critical to develop high-load and high-performance cascades to improve the aerodynamic performance of the compressor.In this paper,the numerical simulation method is used.On the basis of ensuring the overall performance parameters are unchanged,a single-stage high-load transonic fan has been modified.The application of curved,twisted and swept blades in the design of high load transonic fan modify designing and the way to improve the aerodynamic performance of the fan are discussed.In order to obtain a higher single-stage fan design index,the stator or rotor is retained on the basis of the design of the single-stage fan,and the matching design of the tilting,swept rotation blade or end-bending stationary blade is completed using commercial software in the stage environment.In the single-stage fan with tilting and swept rotation blade,the rotor flow field structure is significantly improved by making full use of the design features of axial vane sweep and tangential tilt of the rotation blade.The three-dimensional numerical simulation of a single-stage fan with a end-bending blade vane shows that the application of the end-bending design technique can control the pressure field at the root of the stationary blade,thereby slowing the thickening of the boundary layer along the flow direction.At the same time,the leaf of the blade can be adjusted during the design process.Also during the design process,the distribution of blade profile thickness and the rule of mean camber line transition can be adjusted,the rate of expansion along the local chord length is controlled,the flow of the boundary layer of the suction surface is improved,and the boundary layer on the suction side is suppressed.The matching design between therotation blade sweep,tilt and stationary blade bend,twist and sweep also is completed.The numerical simulation of the design results shows that shock wave and the secondary flow structure in the rotor are effectively controlled by the single-stage fan designed and the accumulation,transition and separation of the boundary layer in the stationary blade suction side corner area are suppressed.The matching relationship between rotation blade and stationary blade is improved.Therefore,it breaks through the design indicators that can be achieved by relying solely on the rotation blade or stationary blade design,and the efficiency of the stage is significantly improved without reducing the surge margin.