A Deterministic Stress Model for Rotor-Stator Interactions in Simulations of Average-Passage Flow

A procedure for modeling deterministic stresses for average-passage simulations of flow in multiple blade-row turbomachines is proposed and tested. This method uses the results of several (two or more) steady Reynolds-averaged Navier-Stokes (RANS) simulations with boundary conditions that are representative of different inflow conditions encountered during the passage of a neighboring blade-row. The deterministic stresses are calculated by averaging the steady results while weighting them with the approximate duration of each inflow condition. This approach incorporates important rotor-stator interactions that are neglected in models based on a swept-wake approximation. The model is tested successfully by computing the deterministic stresses in the stator vane passage of a centrifugal pump, and comparing them with direct measurements using PIV data. Remaining discrepancies between model predictions and experimental data are probably linked to the inability of the turbulence models to account for flow phenomena at each phase, such as mid-vane separation.