| As one of the three core components of marine gas turbine,multi-stage axial-flow compressor adopts transonic stage at the inlet,which is an important technical feature.The layout of transonic flow field in three-dimensional diffuser and the structure of shock wave will have an important impact on the performance of compressor design point and surge boundary under off design condition.In this paper,the aerodynamic layout of typical marine gas turbine compressor in transonic stage is studied in order to provide technical support for improving the aerodynamic performance of marine gas turbine compressor and solving the problem of stability margin.Based on this reason,this paper takes the 1.5-stage transonic stage of a typical marine gas turbine compressor as the research object,with the help of numerical simulation method,studies in detail the influence law of the change of reaction and consistency on the transonic compressor’s aerodynamic performance,and analyzes the mechanism of the effect.This paper studies from the following aspects:First of all,in order to consider the characteristics of the transonic design parameters of marine gas turbine compressor required in this study,the design point parameters of the research object are selected according to the first 1.5 transonic stages of a 9-stage marine gas turbine axial-flow compressor developed by the research group,which respectively go through one-dimensional design,S2 flow surface design,and select the appropriate blade modeling method for three-dimensional blade modeling,and then calculate the flow field After verification and modification for many times,a transonic compressor meeting the design requirements is obtained.Secondly,in order to study the influence of the change of the reaction degree on the transonic stage aerodynamic performance,the average reaction degree is changed by changing the absolute air flow angle at the inlet in one-dimensional design,and the radial distribution of the reaction degree is changed by changing the twist law in two-dimensional design.The overall performance,design point and near stall point of the transonic stage compressor in different schemes are studied The loss of stator and the characteristics of flow field are analyzed.Then,in order to study the influence of consistency change on the aerodynamic performance and internal flow field of transonic compressor,under the condition of constant static blade thickness,the thickness of moving blade can be changed by changing the number of moving blades,and the radial distribution of consistency can be changed by changing the chord length at different blade heights and ensuring the consistency at the root and top of moving blade The overall performance of the transonic compressor,the point under the design back pressure,the design flow point,the loss of the moving and stationary blades near the stall point,and the influence of the flow state of the convection field are analyzed.Finally,by three-dimensional calculation,compared with the 1.5-stage transonic compressor prototype designed at the beginning,the average reaction degree changes at the design speed,and the surge margin increases by 4.75% at most.On the premise that the radial distribution difference of the reaction degree above the pitch diameter is small,the large reaction degree design can be selected for the blade root to improve the transonic compressor aerodynamic performance;with the increase of the average consistency of the moving blade,the peak value increases Under the condition of fixed blade root and constant blade top consistency,the higher the radial consistency,the better the comprehensive aerodynamic performance.At this time,the efficiency is 0.538% higher than that of the prototype,the surge margin is 3.95% higher,and the blocking flow has no significant change. |
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