Before simulating the unsteady (linearized or non-linear) aerodynamic flow around the vibrating
blade row, the first step was the steady state base flow calculation. A structured grid with about
700000 nodes was used for the steady flow simulation with the Traf solver; the k − ω Wilcox highReynolds
turbulence model was employed. Since the test rig exhibits some secondary flows due to
hub leakages through the gaps around blade platforms (these gaps are necessary to allow for blade
oscillations), two additional steady simulations have been carried out on a modified grid (with about
735000 nodes), representing leakage flows with approximate positive and negative injections. These
two models allowed for a more satisfying agreement with the experimental data