Application of deterministic stresses model in simulation of centrifugal compressor stage flow field

The passage-averaged N-S equations proposed by ADAMCZYK is proved to be a more rigorous and complicated model than the mixing plane model in the flow prediction of multistage turbomachinery using steady state methods, in which the deterministic stresses represent the time-averaged effect of the flow unsteadiness. Like the RANS, the average-passage N-S equations do not contain sufficient information to determine its solution. Based on reduced passage averaged N-S equations, a semi-empirical deterministic stresses model is introduced instead of overlapping domain approach. By combining the interface approach with the deterministic stresses model, a steady simulation method is developed to predict the effect of the time-averaged unsteadiness in the centrifugal compressor stage. To verify the developed deterministic stresses model and the corresponding numerical method, two computations for two centrifugal compressors are performed: one is the solution of reduced passage-averaged N-S with the developed deterministic stresses model; the other is of the steady N-S equations with the mixing plane. Two computations cost the similar time. Compared with the mixing plane method, results with deterministic stresses model has a better agreement with the experiment due to considering the time averaged effects of the flow unsteadiness; deterministic stresses compensate the influence of the ″artificial mixing″ with the interface plane, and the deterministic stress model provides more realistic flow field prediction than the mixing plane model.