Abstract: Numerical simulation and analysis of the flow structure inside a centrifugal compressor radial inlet are carried out by using computational fluid dynamics (CFD) technique. The results show that the flow structure consisting of some large vortices is complicated, which leads to flow distortion generating at the impeller inlet and seriously degrades the stage performance. A numerical optimization approach to the radial inlet, based on CFD technique, is developed to improve flow structure and reduce flow loss, and applied to the shape optimization of a centrifugal compressor inlet. A 1.26% improvement of the objective function, isentropic efficiency of the compressor, is obtained, while satisfying the constraint conditions that the mass flow and pressure ratio are not less than those of the original one. The optimization results also show that the developed approach is effective for the optimization design of the centrifugal compressor radial inlet.

Key words: Centrifugal compressor, Computational fluid dynamics technique, Optimization design, Radial inlet