This paper presents a detailed analysis of a centrifugal compressor stage with a vaned diffuser for application in a heavy duty engine turbocharger. The analysis is carried out in order to investigate the capability of a steady-state 3D CFD to predict the pressure distribution resulting from the flow through the stage.
As it is impractical to investigate the whole range of conditions, the first objective of this paper is to define the operating points, which are most relevant to the real operation of the compressor, to be used in this paper. In order to do this, the engine operation is weighted in terms of the total fuel consumption across a reference route: Portland-Pendleton-Portland. After the definition of the primary operating points, a CFD setup is created with regard to previous work on steady-state 3D CFD of a centrifugal compressor stage. The CFD analysis is validated against extensive hot-gas test stand data. The experimental data include the static pressure distribution in the diffuser shroud, determined with an array of 256 pressure transducers. A maximum discrepancy between the CFD and the experiment of around 1.6% difference is achieved for all primary operating points.