NUMERICAL INVESTIGATION OF UNSTEADY BOUNDARY LAYER TRANSITION INDUCED BY PERIODICALLY PASSING WAKES WITH AN INTERMITTENCY TRANSPORT EQUATION

A numerical study was performed to investigate unsteady flow transition under the effect of periodically passing wakes on a highly loaded low-pressure turbine cascade. The simula-tion was done by a time-accurate 2D Navier-Stokes solver, which was developed at the Institute for Thermal Turbo-machinery and Machine Dynamics. The transition process was modeled by coupling a baseline two-equation k-ω turbulence model with an intermittency transport equation via the turbu-lence production term. The experimental investigations on the highly loaded low-pressure turbine cascade, called T106D-EIZ were carried out at the Institut für Strahlantriebe der Universität der Bundeswehr München (Germany). The available experimental data contains three test cases by varying the isentropic exit Reynolds number from 200.000 to 60.000. The objective of this paper is to show the ability of an intermittency transport equation to model unsteady wake in-duced transition and separation mechanisms. The numerical results are compared by the pressure distribution, shape factor and loss behavior to the experiments