DNS of the Flow Near the Endwall in a Linear Low Pressure Turbine Cascade With Periodically Passing Wakes

Direct numerical simulations (DNS) were used to study the effects of periodic incoming wakes on the flow near the endwall in a linear turbine cascade T106. The moving cylindrical bars generating the wakes in the experiment were represented by means of appropriate unsteady turbulent inflow conditions. In the simulations, two cases, with and without incoming wakes, were conducted at a Reynolds number of 90,000 based on chord length and outlet velocity. The results were validated with experimental data. Due to constructive limitations of the experimental setup, the incoming boundary layer is very thin, so that some features of the secondary flow are absent or small. Employing phase-averaging, however, the periodic formation of vortical structures caused by the wakes can be identified in the vicinity of the endwall.