On the Periodically Unsteady Interaction of Wakes, Secondary Flow Development and Boundary Layer Flow in an Annular LPT Cascade: Part 2 — Numerical Investigation

In this work we present the results of the numerical investigations concerning interaction effects between periodically incoming wakes, secondary flow development and boundary layer flow inside a low pressure turbine (LPT) equipped with modified T106-profile blades. The numerical predictions obtained using 3D Unsteady Reynolds-Averaged Navier-Stokes (URANS) simulations are compared against stationary and time resolved experimental results conducted in the same configuration and discussed in part 1 of this 2-part work. For the investigation of the spatial topologies and the dynamics of the coherent flow structures under periodical wake impact, a frequency domain analysis as well as proper orthogonal decomposition (POD) of the unsteady data is proposed and discussed.