Numerical Research Of Effect Of Non-axisymmetric Stator Tip Clearance On Compressor Flow Field With Distorted Inlet

With the development and improvement of the aviation industry,the aircraft engine/gas turbine has become the most strategically important national defense industry in the twenty-first Century,which is the main direction of the industrial development of all over the world.With the continuous improvement of performance indicators such as flight speed and altitude for military aircraft,and the increasing mobility of aircraft special maneuverability,the compressor's stability and efficiency are obviously reduced under the condition of inlet distortion.Therefore,the study of the stability and efficiency of the compressor has become an important direction for the research of the development of the aircraft engine,and understanding of the unsteady flow mechanism and flow characteristic changes with distorted inflow in compressor is important theoretical significance and engineering value.The single stage transonic axial compressor of the Key Laboratory for Small Marine Gas Turbine Technology of Dalian Maritime University is studied in this thesis.First of all,numerical method is used to investigate the flow field structure of the compressor at the peak efficiency point and near stall condition.The result shows that there is huge separation at the top of stator,however,the flow of airflow near the root of the stator is better.Therefore,different structural parameters clearance top structure is tried in this thesis.Afterwards,single channel numerical method is used to investigate the influence mechanism of the structure parameters of the top clearance at the near stall condition,it is found that the leakage flow generated by the top clearance of the stator can reduce the accumulation of low energy fluid in the suction surface and the corner region,what's more,the leakage flow can reduce the choke of flow channels and improve the capacity of stator and compressor margin and efficiency.At the end of this thesis,the stator clearance scheme with the best modification effect is applied to the static blade flow field affected by distortion.Different numbers of stator blades with different clearance are arranged in the distortion affected area,and the influence of different number of stator blade clearance structures on the performance of the compressor is studied.The result shows that the compressor with 9 top clearance stator in the resign of influence of distortion can reduce the separated flow caused by distortion on the suction,and ensure compressor efficiency while improving compressor stability margin.