Development Of Software System For Multi-Stage Centrifugal Compressor Aerodynamics Design And Application In Two-Stage Centrifugal Compressor

At present, there poses a new great challenge for structure and performance of compressors in low thrust military- and small power civil- gas turbine. Except for the designed mass flow, pressure ratio and efficiency, it demands higher requirement for mobility and flexibility. Compared with mutli-stage axial compressors, multi-stage centrifugal compressors have an advantage in light weight and small volume. It becomes an important approach to solve the facing difficult problem by using multi-stage centrifugal compressors. Research and development on multi-stage centrifugal compressors starts relative late in China compared with foreign countries. In order to decrease the technology difference, shorten design period, improve design ability, it is imperative to develop an integral software system for centrifugal compressors aerodynamics design.The procedure of aerodynamics design includes one-dimensional preliminary design, flow passage formation, S2 relative stream surface calculation, blade design and three-dimensional CFD. Because of significant deviation on S2 calculation, this process is usually directly replaced by a simply method that given the angle profile of blade root and tip to accomplish blade design, followed by CFD verification. The main work on algorithm in this thesis is introduced below.1. Improving the single-stage centrifugal compressors' model in preliminary design. Adding the module of crossover channel and return channel. Adding the algorithm of pressure ratio distribution and parameter optimization. Accomplishing the preliminary design model of multi-stage centrifugal compressor.2. Developing the formation algorithm for the multi-stage centrifugal compressor's flow path. Developing the blade design technique based on ruled-surface. Realizing the interface between program and CFD software.3. Developing the algorithm for visualization in design based on OpenGL techniques and making the design and result integral.4. Accomplishing all the program code on computers. Protecting all the algorithm by encapsulating them into dynamic link library.Then, this thesis develops a graphic software system with favorable user interface based on these algorithms and realizes the rapid aerodynamics design on centrifugal compressors. The subsequent work on this software system is as follows.5. Calculating the Krain Impeller on the system and comparing results and designed data. The contrast shows that the precision is within acceptable range and verification of reliability and accuracy of models and algorithms has been done.6. Designing a multi-stage centrifugal compressor given the condition of certain mass flow and pressure ratio. Verifying the design on NUMECA and making aerodynamics analysis on some influence factors.