The Optimization And CFD Analysis Of Centrifugal Compressor With Long-short Blades

The centrifugal compressor has the characteristic of small flow, low power, highspeed and high reliability, which has applied more and more in the energy, chemical,and aviation industry. Now the centrifugal compressor is developed toward small size,high pressure ratio, high efficiency and low energy consumption, which make itsdesign requirements stricter. In the centrifugal compressor with high speed, highpressure, the impeller widely uses the long-short blades, and its various performancetargets such as compression ratio, efficiency draw more and more attention. For thefurther development of higher performance centrifugal compressor, it needs deeperresearch on internal flow field of the impeller. In this context, this paper used CFDtechnology to simulate the first stage internal flow field of a multistage centrifugalcompressor, and to research geometrical parameters influence on the performance ofthe centrifugal compressor stage. This article mainly was divided into five parts,which contain aspects below:Firstly, the topic research background, purpose and significance are introducedand the progress at home and abroad of the numerical simulation and its experimentalstudy of the centrifugal compresso are discussed; Secondly, the mathematicalcalculation methods are discussed, including CFD general process of the solution, thecommercial CFD software with current more extensive application. Combined withFLUENT software, the basic control equation, turbulent model, grid partitiontechnology, the setting of boundary conditions in the impeller internal flow fieldcalculation are analyzed; At the same time, the centrifugal compressor model andnumerical calculation method of this study are given. In order to verify the reliabilityof the calculation method in this paper, we simulate a impeller with similargeometrical structure, the numerical calculation and experimental values arecompared, the results show that the calculation method is feasible.In this paper, we redesign the compressor by two ways. Firstly, we obtain fivedifferent form impellers by changing the relative position of the long and short blades on the impeller, through numerical calculation, the external performance and internalflow field of the five impellers are compared, which is a reference to the design of thelong-short blade form of the centrifugal compressor. The second way is cutting theimpeller outer diameter on the impeller meridional plane. we obtain three differenttype. The three different meridional line impellers are simulated, the analysis providesthe reference to the expanding of the impeller model level and rapid development ofthe centrifugal compressor.