Exploration On Centrifugal Compressor Aerodynamic Design With Total Pressure Ratio Of 11

As one of the three core components,the performance of the compressor directly affects the performance of the air/ship/ground gas turbine.Centrifugal compressors have been widely used in vortex/turboprop engines and small and medium-sized gas turbines due to their high pressure ratio,simple structure and small size.As the overall performance requirements continue to increase,the demand for high pressure ratio centrifugal compressors is increasing.Although the three-dimensional flow of the centrifugal compressor is extremely strong,the multi-levels of its design theory and system are still clear: one-dimensional design gives a scheme,through-flow design gives detailed flow,modeling gives three-dimensional blade geometry,three-dimensional CFD analysis optimization,but For a high pressure ratio centrifugal compressor with a total pressure ratio of 11,its aerodynamic design is still extremely difficult,which is mainly reflected in the loss of referability of the flow design.Under this technical background,this article has carried on the aerodynamic design exploration to the total pressure ratio 11 centrifugal compressor.First of all,in order to ensure the reliability of the CFD tool used in aerodynamic design,the CFD software used in this paper was verified in detail for the case of a centrifugal compressor.Secondly,the basic principles of the current aerodynamic design system for centrifugal compressors of the research group were interpreted and introduced,and the one-dimensional program design and flow design procedures were initially verified to ensure the accuracy of design tools.Based on the above-mentioned aerodynamic design system,the aerodynamic design of the high pressure ratio centrifugal compressor stage was carried out with the design of the total pressure ratio 11 and the efficiency of not less than 77%.During this period,the overall design of the high pressure ratio centrifugal compressor was obtained from the one-dimensional design.Geometric parameters,and through repeated evaluation of characteristics,parameter optimization,to determine the overall design program;based on this,through the flow program for detailed design,to obtain the relative airflow angle distribution at the front and tail edge of the blade to form a reference for subsequent blade design Based on the use of arbitrary middle arc surface modeling,the detailed design of the optimal impeller is completed through repeated iterative optimization with 3D CFD analysis;finally,the radial diffuser size parameters are determined according to the radial diffuser design criteria,combined with the compressor class Three-dimensional CFD was repeatedly corrected to obtain the best design results.Finally,three-dimensional CFD analysis showed that the designed compressor has a total pressure ratio of 11.7,an adiabatic efficiency of77.2%,and a working margin of 11.3%.Finally,the effects of the number of splitter blades and tip clearance on the aerodynamic performance of the centrifugal impeller were analyzed.The results show that increasing the number of splitter blades can increase the impeller pressure ratio and margin,but excessive splitter blades increase the loss.The tip clearance is not entirely negative for flow,and the presence of a small tip clearance can improve the flow of the impeller.