Investigations Of The Flow And Parameter Matching Of A Supercharger Compressor

Not only does supercharger technology improve the development of internal combustion engine technology,but it is also an effective measure to improve the combustion process,raise fuel economy,reduce emissions and meet the increasingly strict emission regulation.Pressurization technology makes up for the deficiency of the naturally aspirated engine,ensure that under the condition of same power,it can reduce engine emission and increase efficiency.At the same time,it is complied with the call of energy saving and emission reduction.The design of centrifugal compressor,which is one of the cores of the supercharger,has a great influence on the performance of supercharger.Lots of manpower and financing have been spent on studying the centrifugal compressor,since the centrifugal was invented.In our country,the study on centrifugal started from the 1970s;technology lags far behind the international average level.More work is necessary to improve the ability of design centrifugal compressor.The detailed flow analysis in a centrifugal with high rotation speed and high load small is undertaken in the paper.The main content in the paper is listed as follows:1.Numerical methods are used to analyze the flow characteristics of centrifugal compressor;the distorted flow distribution phenomenon and its mechanism are studied in detail.It is found that there is a small area of the low speed region near the shroud and high-speed flow distortion at the top of the impeller,which further influences the flow distribution in pressure surface.2.Investigations are performed to study the effect of the backsweep on the performance and internal flow characteristics of the compressor.The conditions with tip clearance and without clearance are inquired separately.The influences of development of shock wake and flow separation to mainstream is studied,which appears at the leading edge of main leafs.The analysis shows that backsweep has great effect on centrifugal compressor with high speed rotations.And not only can the downstream but upstream of flow be influenced.The inlet air and shock wake have also are affected.As the tip clearance has large effect on the internal flow and performance,different sizes of the tip clearance are applied to the impeller to study the influence of tip clearance of tip clearance on the interaction between the shock wave and tip clearance leakage and leakage loss.3.Based on numerical analysis,regression analysis is used to make sure the quantitative relation between backsweep and pressure-ratio.Sample data are disposed by using of linear regression and curve fitting,which is the result of numerical analysis.The best backsweep can be evaluated by regression equation which is from regression.The article has conducted a study on internal flow and performance of supercharger compressor,investigated the influence of backsweep and tip clearance on aerodynamic performance,and analyzed the quantitative relation between backsweep and pressure-ratio.The result of study shows that the internal flow of centrifugal compressor is complicated.To investigate the factors that affect the performance of centrifugal with high speed rotation can supply efficiency suggestions for improvement direction and theoretical foundation.