Aerodynamic Design And Flow Structure Analysis For A Multi-stage Compressor

High-efficiency,high-pressure ratio and high-reliability have always been the design objectives for the modern aircraft engine,but the throughflow design of multi-stage compressor is the technical bottleneck in engine development due to the wide range of technologies and the great difficulties.Therefore,the investigation of advanced multi-stage high-pressure compressor will be a potential technological approaches for developing the overall performance of aerospace power system.Based on such understanding,the aerodynamic design research for the E3 high pressure compressor of General Electric Co.is presented in the dissertation,while CFD technology is applied to analyze the blade passage internal flow structure.And associated features between the aerodynamic performance requirements and the internal flow structure of multi-stage compressor are discussed for providing technological reserve in the advanced design technology of the high-pressure compressor research.One-dimensional design and Q-3D(quasi-three-dimensional)design are first applied to detailedly research and analyse the E3 10-stage high-pressure compressor.The meridional flowpath similar to the true flow path of E3 compressor is obtained by the one-dimensional design method.On account of this work,the total aerodynamic performance and the throughflow aerodynamic layout of the compressor are predicted by the quasi-three-dimensional program.The research results further validate that the design programs have the superior solution precision and the favorable prospect in engineering application for high-loading multi-stage axial flow compressor design issues.On the basis of the Q-3D design,the blade passage for the front five stages of E3 compressor is created combing with the Q-3D aerodynamic parameters and the key geometrical characteristics,while the variable guide vanes and stators are induced and the association regularity in the midst of the variable schedule for those adjustable blades,the compressor aerodynamic performance and the distribution of flow field parameters for blade passage is analyzed detailedly with the aid of 3D numerical simulation method.The study results prove that,in the initial scheme,the compressor performance parameters at design point almost meet the design requirements,however the mass flow rate at the highest efficiency point is nearly equal to the stall mass flow rate making the stable operation range of the 5-stage compressor narrow.After setting angles of those variable guide vanes and stators adjusted,the aerodynamic matching characteristics among each blade row are changed.The corner separation on the part area of blade surface becomes more serious which reduces the compressor efficiency and total pressure ratio,whereas the boundary layer separation on the stator blade suction surface of the last stage is effectively suppressed as well as the through-flow capability and the stable operation range for part rotating speed availably enhanced.As a complete unit,the technology of inducing the variable guide vanes and stators is beneficial to the compressor combination performance,but its defect is exposed at the same time.With a view to the drawback of the above technology,the 5-stage compressor with variable guide vanes/stators is taken as the prot otype,and the aerodynamic optimization design of the problem blades is developed based on the stage-matching of blade flow angle.And the correlation features among the optimized design thought,the performance and the flow structure of the compressor are also presented.The research results reveal that the optimization method improves the flow angle matching of key rotors and stators only with a few optimization variables,which not only enhances the aerodynamic matching characters for blade rows,but als o changes the circumferential inclination angles of blade partial areas.And the radial migration of the low energy fluid in the boundary layer around blade coner is promoted by improving the self-organizing capability of blade passage,adjusting the distribution of pressure gradient and restructuring the aerodynamic loading,so the loss of the flow separation generated by the concentration of the high-entropy fluid is reduced.As a result,the applying of the optimization method developments the adiabatic efficiency and the stable operation range of the compressor,and the technology for the matching of flow angles proposed by this paper could provide a beneficial guidance for the further optimal design of the multi-stage compressor.