A model for potential deterministic effects in turbomachinery flows

The unsteady interaction between blade rows due to a potential field is very important in highly loaded compressors because of its impact on operating performance. In this context the interactions of a flat plate wake with an upstream running pressure wave is investigated numerically using the compressible Navier-Stokes solver TRACE. Several flow conditions regarding Reynolds number, pressure wave amplitude and the axial position of the wave entry plane are examined. The observed phenomena and dependencies are used to develop a transport model which adds deterministic stresses by means of source terms to. the stationary simulation. Calculations based on the proposed model are described and compared with the time-accurate and steady-state numerical simulations. The model captures the influence of the unsteady effects on the time-mean flow accurately and yields a speedup factor of approximately two orders of magnitude compared to time-accurate simulations.