Numerical Simulation On Small Blade Swept Design Of Transonic Fan Rotor

With the development of computer technology,research on advanced pneumatic method becomes more exact and easier by numerical simulation,especially for complex geometry not easy to experiment.This paper selects the splitter vanes of small blade front-swept design on a transonic fan rotor to research.Small turbofan engine has unique technical advantages because it emphasizes less cost, higher reliability,broader scope of work and the technical of splitter vanes has characteristics of small axial size,big amount of finish and better variable condition performance. At present, there are no articals of small blade front-swept design to be published. This paper repeateds contrast design to small straight grain surface blade, makes three-dimensional in the whole glue gap with second order accuracy TVD format of numerical simulation by NUMECA software, the total grid points of two flow channels up to700000,and acquires a whole working curve under the rotor’s design speed.After post-processing to the cross section S1and S3,on average of circumference and the limit of wall streamline analysis,we found that the efficiency of small blade front-swept design under design conditions can increase0.3%and flow capacity is basically the same compare to normal solution for the fan rotors which this paperselects. Small blade front-swept can affect the position and strength of normal shock wave in flow channel,but can’t affect the shock wave at the top of the small blade’s pressure side. Close to surge condition,firstly low speed area appears in the back of the wave foot position at the top of big blade’s suction surface,then for the development of separation of flow, two flanks’ speed becomes different after enter into fow channels on both side of small blade,even small blade front-swept can’t control the boundary layer flow. Close to congestion point,small blade swept can affect the kind of "λ" shock wave’s position and strength,and reconstitute divergent pressure form and load distribution.The influence law of small blade front-swept for rotor performance what this paper obtains has good guiding significance.