Numerical Investigation Of Self-Recirculating Casing Treatment In The Transonic Axial Compressor

With the rapid development of aviation industry,the manufacturing and design level of gas turbine has become one of the important symbols of a country’s industrial level,military strength,and comprehensive national strength.And as a important part of a gas turbine,the compressor plays a key role in the overall performance of the gas turbine.For compressors,increasing their stall margin has always been an important part of gas turbine design.Compared to traditional endwall treatment technology,self-recirculating casing treatment has the advantage of increasing the stall margin of the compressor without reducing the efficiency of the compressor.The transonic compressor Satge37 is the research object in this paper.Using numerical simulation,it firstly explores the flow law of Stage37 under different working conditions and the key factors causing stall,Based on that,the mechanism of the discrete self-recirculating casing treatment and the influence of different jet positions on the performance of the compressor are explored.Then a series of research work on the influence of different forms of full-circumferential self-recirculating casing treatment on the flow of the tip region of the compressor have been carried out,and a full-circumferential self-recirculating casing treatment with good stability enhancement was designed,the research work of full-circumferential self-recirculating casing treatment in this paper provides reference for others.It shows that at the design speed,the discrete self-recirculating casing treatment can effectively suppress the broken extent of the leakage vortex at the tip of the rotor、eliminate the range of low relative total pressure gas in the tip zone and delay the occurrence of stall.The study of different jet positions shows that the casing treatment for the jet position at the upstream of the rotor is the best for the stabilization,and the casing treatment for the jet position around the leading edge of the rotor has the strongest inhibitory effect on the leakage vortex breaking.At the design speed,the study of the full-circumferential self-recirculating casing treatment found that the jet axial velocity and the jet quantity are the two key factors affecting the flow in the tip region.By installing the airfoil shape baffles in the full-circumferential self-recirculating casing treatment,the circumferential speed of the airflow can be effectively eliminated,the axial velocity of the jet can be increased,the flow area of the tip region of the rotor can be enlarged,and the stall margin of the compressor can be improved.