Full Annulus Simulation of a High-Speed Centrifugal Compressor Using an Unstructured RANS Flow Solver

Abstract

This paper presents numerical simulations for a high-speed centrifugal compressor using an unstructured Reynolds averaged Naiver-Stokes flow solver U2NCLE. It solves three-dimensional compressible governing equations using an arbitrary Mach number solution algorithm. The stability enhancement for a centrifugal compressor was achieved by injecting air streams into the vaneless region of the diffuser. Numerical prediction of the stabilizing effect of air injection in the centrifugal compressor requires full annulus simulations of the compressor system. This work presents numerical procedures for simulating full annulus centrifugal compressor, including air injection modeling. A sliding technique is employed to handle relative motion grids for impeller and diffuser interactions. Computed results for the centrifugal compressor are analyzed and assessed with the experiment.