Study On Aerodynamic Performance And Circumferential Groove Casing Treatment Of A Two-stage Axial Compressor

Axial-flow compressor is one of the key components in flow systems and are widely used in various fields in industry.Under the low-flow conditions,unsteady flow phenomena such as stall and surge may occur inside the axial flow compressor,bringing great hidden dangers to the stable and safe operation of the compressor.Therefore,studying the stall phenomenon of compressors and expanding the stable working range of compressors have always been the focus of attention in industry.In this paper,two methods of experimental measurement and numerical simulation are used to analyze the aerodynamic performance and expand stability of a industrial two-stage axial compressor.The specific research content and results are as follows:1.Establish single passage and four passages calculation models for two-stage axial compressor.Compare the results to show that the four passages model has the advantage of finding circumferential non-uniform phenomena.Discuss the meshing of the computational models,the computational residuals and the spatial discrete formats.Compare with experimental results to verify the reliability of the computational method.2.Using the unsteady four-passages model,observed the change characteristics of the flow parameters near the tip clearance under the condition of small flow.The causes of compressor stall were explained,and it was verified that the flow separation of the suction surface at the top of the rotor blade was the main reason for the stall of the compressor.3.The experimental and numerical simulation methods were used to study the matching characteristics of the rotor and stator blades at different speeds,and the optimal angle structure of the compressor was found to be the SR＿65＿65 structure,and the aerodynamic performance of the inter-stage matching was explained.4.Established several circumferential groove models and find that the circumferential groove model can improve the performance and working range of the original model.Among them,the expansion effect and performance improvement of the full-covering circumferential groove model are the most obvious,which can improve the overall working range of 13.5%,the static pressure rise of the highest efficiency point of 20.2%,and the efficiency of 2.9%.By analyzing the flow field,it is found that the circumferential groove structure can supplement the flow in the separation area of the suction surface at the top of the rotor blade to suppress the occurrence of separation phenomenon under small flow conditions.The research in this paper is helpful to understand the internal flow structure of multi-stage axial-flow compressor,and provides a basis for the aerodynamic design of multi-stage high-performance compressors.