Numerical simulation of the unsteady impeller- diffuser interaction

A numerical method for the calculation of unsteady impeller/diffuser interaction in centrifugal compressor stage of arbitrary pitch ratio using time-inclined operator is presented. The viscous stress terms are not neglected in the viscous flow computation. The unsteady flowfield of a centrifugal compressor is simulated and compared with the experimental data and commercial software. The unsteady computation using the time-inclined operator is in best agreement with the experimental data. It shows the unsteady simulation using time-inclined method is able to capture the flow behavior quite successfully, and the program developed by the author can predict the flowfield in the centrifugal compressor accurately.