Deterministic stress analysis in centrifugal compressor using non-linear harmonic method

Numerical simulation on a centrifugal compressor is carried out to investigate the differences of flow fields between time-averaged and steady state as well as the distribution characteristics of deterministic stress. It is found that the macro flow structure of time-averaged and steady flow field is generally similar but flow details differ a lot. The differences in flow details are identical to the distribution of the deterministic stress, which improves the facts that deterministic stress is the reason of leading the differences between time-averaged and steady flow behavior. Results also show that the deterministic stress increases along spanwise gradually and is in high level and with strong variation in the region near impeller exit, which reveals strong flow unsteadiness in corresponding region, caused by strong tip leakage vortex and secondary flow vortex.