An Optimization Method for Centrifugal Compressor Design Using the Surrogate Management Framework

A variety of centrifugal compressors are used in various fields of industry these days. The design requirements are more complicated, and it is difficult to determine the optimal design point of a centrifugal compressor. The aim of this study was to propose an efficient optimization method for centrifugal compressors considering the impeller, the vaneless diffuser, and the overhung type volute. The optimization was performed using the surrogate management framework (SMF). The design parameters were the impeller exit radius, the exit blade angle, and the flow coefficient. Sample points in the design space were selected according to the Design of Experiments (DoE) theory. The CFD simulations were executed on the impeller and the diffuser at every sampled point. The volutes were described using a one-dimensional but reliable theory to reduce the simulation time. An approximation model based on the Kriging method was constructed using this dataset. Then, an optimal design point that minimized the objective function was determined in a substitute design space using the pattern search method because of its efficiency and rigorous convergence. The optimization process, underlying methods, and results are described in this paper.