Research On Scale Reduction Modeling Design Of Axial Compressor

As the power plant of aircraft and ships,gas turbine is the "heart" of aircraft and ships.Its development level is the concentrated embodiment of a country’s industrial level,comprehensive national strength and scientific and technological level.As one of the three major components of gas turbine,compressor has an important impact on the performance of the whole gas turbine.At present,the development level of gas turbine in China is relatively low,so it is urgent to develop high-performance compressor.As a design method with less time and cost requirements,similarity modeling is widely used by researchers.The performance of the compressor designed by modeling is similar to that of the parent compressor,which saves a lot of manpower and material resources.In scaleup modeling,it is necessary to ensure that the model machine and the parent machine meet the similarity conditions.However,in the actual scale-up modeling,it is impossible to ensure that all the similarity criteria meet the requirements.For example,Reynolds number and roughness are difficult to meet the similarity criteria.As a result,there are performance differences between the modeling machine and the prototype machine.Therefore,it is necessary to make a specific analysis of its impact and correct it in performance conversion.Based on the above,this paper mainly carries out the following work:The prototype two-stage semi axial compressor is modeled by UG modeling software.The prototype two-stage semi axial compressor is meshed in the Auto Grid module of NUMECA software,and the speed is adjusted and the appropriate number of grids is selected.The simulation results are compared with the experimental values,so as to verify the rationality of the meshing method and calculation model selection adopted in this paper.Then,the formula of the modular scaling principle of the prototype two-stage half compressor is deduced to ensure the three principles of similarity,namely geometric similarity,motion similarity and dynamic similarity.Two kinds of modular compressors with modular coefficients of 2.0 and 3.0 are obtained,and a new geom Turbo file is written.Then,the influence of different rotating speeds on scale reduction modeling is explored.Set 100%speed,80% speed and 60% speed respectively,get the compressor performance characteristic curves with different modeling coefficients at different speeds,and compare the performance and analyze the internal flow field.The effects of Reynolds number and roughness on the process of scale reduction modeling are explored.According to the gas equation of state,by changing the inlet back pressure to make the inlet Reynolds number of the modeling machine the same as that of the prototype,compare and analyze its performance,and explore the influence of Reynolds number on scale reduction modeling.By changing the roughness of compressors with different modeling coefficients,the performance curves of modeled compressors with different roughness are obtained.Combined with the internal flow field,the influence of roughness in modeling design is explored.Finally,the performance efficiency curves of compressors with different modeling coefficients are corrected by Casey method,and the correction results are analyzed.Combined with the analysis of specific correction results,a more accurate performance correction method is proposed,and the feasibility of the correction method is verified.