Direct numerical simulations of the unsteady secondary flow in the near-wall region of a linear low pressure turbine cascade

Regarding gas turbines and jet engines, the design and the optimization of modern highperformance turbines and compressors towards reduced emission and augmented performance requires a clear understanding of the engine's aerodynamics, especially, of the unsteady secondary flow on the endwall. Direct numerical simulation (DNS) provides one of only few possibilities to shed new light on the physics of this highly unsteady, transitional, and three dimensional flow. The present thesis deals with DNS of the secondary flow in a linear low pressure turbine T106A cascade at a low Reynolds number of 20000. The major aim of the work is to improve the understanding of such flows, which is achieved by detailed analyses of the secondary flow structures and their dynamics. Taking into account the inuences originating from periodically passing wakes and the rotation of the system, four different cases are simulated.