Stator elements optimization of centrifugal compressor intermediate type stage by CFD methods

Abstract

<jats:p>Optimal gas-dynamic design is a complex and time-consuming process. Modern CFD methods help in solving optimization problems and reliably calculating characteristics of stator elements of centrifugal compressor stages. To carry out such calculations, it is necessary to create a parametrized model, which facilitates automation of the process of changing the flow path geometry, rebuilding its dimensions and the computational grid. Using the Direct Optimization program of the ANSYS software package, we have optimized the flow path of the stator elements of a centrifugal compressor intermediate type stage consisting of a vaneless diffuser and a return channel. In this paper, the MOGA (Multi-Objective Genetic Algorithm) optimization method was used. The object of the study was stator elements of one of the model stages designed by the Problem Laboratory of Compressor Engineering, SPbPU. The goal was to achieve the minimum value of the loss coefficient of stator elements when changing 5 geometric parameters: the number of vanes, the inlet vane angle, the height of the vane at the inlet to the return channel vane cascade, the radius of curvature of the leading edge and the thickness of the vane profile. For the best variants based on the results of optimization, the characteristics of the loss coefficient depending on the flow rate coefficient were calculated, their characteristics were compared with the initial variant of the stator elements. The best variant in the design mode has a loss coefficient 4.4% lower than the reference model. With a flow rate coefficient of 1.63 times greater than the calculated one, the optimized variant’s loss coefficient is 33% less.</jats:p>

Optimization of Return Channels of High Flow Rate Centrifugal Compressor Stages Using CFD Methods

“…In this respect, the preliminary design can be considered satisfactory. However, unlike the preliminary design of the low flow rate stage in the Figure 2 [20], the minimal loss coefficient does not correspond to Φ des . The preliminary design formulae should be corrected towards an increase of the inlet area of vane channels.…”

“…Parameters max δ and LE R were studied in [20]. The test results and CFD calculations of the model stage with des Ф = 0.028 are presented.…”