Research On Aerodynamic Configuration Method Of Low Pressure Compressor Of Marine Gas Turbine

Since the launch of the major projects of aero-engine and gas turbine,as an important part of the national manufacturing power construction strategy,the design and development of marine gas turbine compressor has been deeply concerned by a large number of scholars because of its high technical difficulty and long development cycle.The study of aerodynamic design methods and rules of multistage axial flow compressors is of great significance for accumulating design experience,reducing design cost and improving design efficiency.One-dimensional initial design and S2 through-flow calculation are important parts in compressor design system,which are characterized by fast calculation but high dependence on empirical model.In order to explore the aerodynamic layout rules,a sufficient number of calculation samples are needed.This paper mainly focuses on the design and analysis of one-dimension and S2,supplemented by three-dimensional CFD calculation,and conducts an in-depth study on the aerodynamic layout methods of multistage axial flow compressors.First of all,based on the previous research on S2 through-flow calculation empirical model,a set of empirical models with strong universality and high flexibility,suitable for marine multistage axial flow compressor is summarized through comparative analysis,and the S2 positive problem calculation program is developed on this basis.By comparing the S2through-flow prediction results,experimental measurements and three-dimensional CFD calculation results of different types of compressors,the feasibility of the S2 positive problem program is verified.The S2 loss model is modified by scaling technology to improve the prediction accuracy.Then,based on the one-dimensional design and analysis method,the comprehensive influence of the distribution mode of flow coefficient,load coefficient and reaction degree along the stage on the pressure ratio,efficiency,surge margin and diffusion factor of the design speed is studied,in which the distribution curve of flow coefficient and load coefficient adopt cubic function,and the reaction degree is a two-straight line.For the 8-stage low-pressure compressor studied in this paper,it is found that the peak position of flow coefficient is at the 6th stage,the load coefficient is at the 5th stage or the 6th stage,and the reaction degree of the 4th stage is in the range of 0.5～0.52 with high efficiency.On this basis,the mathematical model of the distribution curve of key design parameters in the one-dimensional design is extracted.By means of Smith diagram,the matching rules of flow coefficient,load coefficient and reaction degree are qualitatively studied,and it is found that the distribution of reaction degree and load coefficient have a strong influence on the efficiency of each level at the design speed,and the reaction degree has a greater influence on the latter stage.Next,based on the S2 inverse problem and S2 analysis code calculating program which is developed,this paper studies the S2 twisting law of 8-stage low-pressure compressor.It is found that the transition from the equal reaction degree to the equal circulation distortion law from the first stage to the last stage is effective.On this basis,the characteristic curves under different options of blade tip circulation and reaction degree are compared,and the optimal distortion scheme is obtained.Finally,in order to further find the aerodynamic configuration rules and optimization direction of the multi-stage compressor,the optimization method based on the optimization theory is carried out.The optimization program is developed according to the theory of genetic algorithm,and its global character is verified by the test function with local trap.By combining the optimization method with HARIKA algorithm,the influence of flow coefficient,load coefficient and reaction degree distribution mode on the performance of the whole working condition is studied.The design parameter distribution curve is optimized with different performance indexes.The research shows that the flow coefficient distribution has a great influence on the surge margin of the low-speed working condition.The genetic algorithm combined with Bezier curve parameterized modeling method,the middle section profile of the final stator blade was optimized,The optimal surface load layout characteristics are obtained.optimize the blade thickness distribution curve from the initial profile has great change,the biggest thickness forward,total pressure loss coefficients falls at low Mach number under different attack angles.The optimization module was combined with the one-dimensional analysis program to optimize the rotation angle of the inlet guide vane and the first three static blades of the compressor at a speed from 100% to 50%,which significantly improved the stable working range under low working conditions.