Study On Improvement Of Compressor Rotor Anti-Total Pressure Distortion Capacity With Blade Tip Winglet

Compressor is one of the core components of aero-engine,and its performance directly affects the performance of the engine.With the increasing requirements of aero-engine,the inlet total pressure distortion will inevitably occur,which will lead to the reduction of compressor efficiency,pressure ratio,stability margin and other performance parameters.In serious cases,it will also cause stall and surge of compressor,threatening the safety and stability of flight.Therefore,it is necessary to improve the ability of compressor to resist inlet total pressure distortion to meet the higher requirements of flight work.Tip winglet is a kind of passive flow control technology which has been widely concerned in recent years.In this thesis,the pressure-side winglet is applied to enhance the ability of compressor rotor to resist inlet total pressure distortion(1)Two types of inlet radial total pressure distortion are designed,which are "tip distortion" and "hub distortion".The "tip distortion" causes the total pressure and axial velocity to decrease gradually from hub to casing and reach the maximum value near the hub.On the contrary,the total pressure of gearbox is the highest and that of hub is the lowest.The results show that the maximum isentropic efficiency decreases by 0.23% when the blade tip is distorted,but it can improve the total pressure ratio near stall.When the hub is distorted,the total pressure ratio of the compressor is reduced and the maximum isentropic efficiency is reduced by 0.55%.The installation of the pressure-side winglet does not change the vortex structure in the passage,but reduces the strength of the tip leakage vortex,thus reducing the scope and strength of the low-speed recirculation zone after its rupture,improving the flow condition,and thus delaying the stall.The stability margin increases by 12.5% and 2.4%respectively for inlet tip distortion and hub distortion.(2)At 100% and 80% speed,three kinds of circumferential distortion are calculated,and the circumferential distortion angles are 180°、90° and 60°.The results show that at 100%design speed,the distortion angle is 180°、 90°、60°.The maximum isentropic efficiency decreases by 0.3%,0.4% and 0.3% respectively.The stability margin was increased by 2.7%,2% and 6% respectively.At 80% of the design speed,the total pressure ratio curve moves to the left and down,and the maximum isentropic efficiency is 180°、90°、60°.The stability margin increases by 8.8%,2% and 0.7% respectively.By blocking the tip leakage flow,the pressure-side winglet reduces the strength of the tip leakage vortex and the interaction between the tip leakage vortex and the passage shock wave,so as to improve the flow capacity of the rotor and achieve the purpose of stability expansion.