Calculation Of Stall Margin Improvement In Aeroengine Compressor With Swept Rotor

The instability of aeroengine has always been a hot topic in turbomachinery aerothermodynamics.How to ensure that the compressor has a large stability margin under high stage pressure ratio is very important for improving the reliability of aeroengine.Some studies showed that the tip overflow of the rotor is closely related to the rotating stall.Based on this,this paper introduced a method to modify the rotor to increase the surge margin and improve the anti-distortion ability.In this paper,the influence of rotor modification on compressor performance is obtained by numerical simulation.In this paper,three methods are used to modify the rotor types based on NASA Rotor 37.The performance data of the new rotor types is obtained by solving Reynolds-averaged Navier-Stokes equations,and the mechanism of stall margin improvement is analyzed.At the same time,the inlet distortion of engine nacelle under the crosswind condition is studied as the input data reference for simulating the anti-distortion ability of new rotor types.According to the results of numerical calculation,the surge margin of the rotor with alternately backward swept is the largest,reaching 11.54%,while the surge margin of the two new rotor types with 0.002 m alternately forward swept,12% chord length of forward swept in 100% span and 4% chord length of forward swept in 99.5%span also reach up to 8%,and the surge margin of the basic type is only 4.26%.Because the axial position of the blade is not synchronous,the flow field in the adjacent passage is not consistent,which slows down the generation of rotating stall.The tip clearance expanding results in a reduction in the surge margin of the rotor.The peak efficiency of the rotor type with 0.002 m alternately forward swept decreased by2.13% and surge margin of this rotor type decreased by 7.61% for three times tip clearance.The inlet distortion of engine nacelle at 135° crosswind is more severe than that at 45° crosswind,especially the gas flowing through the passage between engine nacelle and the ground strengthens the ground effect,which leads to the strong inlet distortion.The modified rotor types obtained the great anti-distortion ability.