NUMERICAL PREDICTION OF UNSTEADY TRANSITIONAL BOUNDARY-LAYER CAUSED BY ROTOR-STATOR INTERACTION

The objective of the research reported in this paper was to develop co mputational techniques for the prediction of transitional hows associa ted with the rotor-stator interaction in turbomachinery. Three low-Rey nolds-number turbulence models were incorporated in the Navier-Stokes code and evaluated for accuracy in predicting the onset and end of uns teady transitional patches caused by wake passing. The best model was then used for the modification and improvement of the leading-edge eff ect. A comparison with the experimental data indicated that the qualit y of prediction was as good as those derived from an unsteady boundary -layer code. A comparison of the instantaneous shape factor, the skin friction coefficient, and the momentum thickness indicated that the Na vier-Stokes predictions were reasonably good and should aid the design ers of turbomachinery in allowing for the unsteady transitional flows caused by rotor-stator interaction. The simulation results were interp reted to derive new insight on the flow physics associated with transi tional flow including turbulence properties.