The Influences Of The Impeller Geometric Parameters On The Performances Of The Centrifugal Compressor

In purpose of investigating the influences of the impeller geometric parameters on the performances of the centrifugal compressor,numerical simulations are carried out on the J60 turbocharger compressor.Research contents are as follows:Firstly,by means of numerical simulation technology,the flow mechanism in centrifugal compressor under different boundary conditions were investigated.Results indicate that the tip leakage flow of impeller,and the large scale flow separation in impeller passage were the main effects of centrifugal compressor's design condition and near surge condition.Secondly,the impacts of the impeller geometric parameters on the performances of the compressor in different conditions were studied.Contents and conclusions are as follows:1.Influences of the impeller inlet geometric parameters?1?D₁/D₂ has great impact on the efficiency and chock boundary.With the decrease of the number of D₁/D₂,the high efficiency area is shifted towards low speed and small massflow area;At the same time,the surge boundary massflow is decreased,making the map move towards left.As for the centrifugal compressor of J60.The optimum value of D₁/D₂ is about 0.676.?2?The change of d/D₂ has great influence on the location of high efficiency area of the centrifugal compressor.With the increase of d/D₂,the compressor performance map is shifted towards the high pressure ratio and the big massflow area;2.Influences of the impeller outlet geometric parameters?1?b₂/D₂ has an important influence on the efficiency,pressure ratio and chock boundary.With the increase of b₂/D₂,the map is moved down.As for the centrifugal compressor of J60.The optimum value is about 0.0955.?2?The value of?_2bhas great impact on the efficiency of small massflow area.With the increaseof?_2b,the efficiency of small massflow area of centrifugal compressor is improved.3.Influences of combined effect of the inlet and outlet geometric parametersWith the decrease of the inlet area and outlet area while A₁/A₂ is kept constant,the high efficiency area of the centrifugal compressor is shifted towards to the low pressure ratio and the small massflow area.