Detailed flow analysis of a transonic low pressure turbine at low turbulence levels

Abstract

Geared turbofan technology allows low pressure turbines to work at faster rotation speed. On the other hand, the condition in flight implies low density, resulting in a combination of high Mach number and low Reynolds number. The objective of this master thesis is to realize a first 2.5D DNS analysis of a new blade designed for these conditions.

In order to do so, the mesh was realized with Gmsh and two different combinations of Mach and Reynolds number were resolved using the discontinuous Galerkin method solver Argo on the Tier-1 Walloon supercompter. These two conditions will provide a range of values in case this blade is tested in a wind tunnel. With the provided results different analysis were performed in order to have a first understanding of the complex flow behaviour and to compute first performance coefficients.

Complex mechanisms such as a weak shock on the suction side and a turbulent reattachment on the pressure side were observed. Thus different analysis such as Fourier transform were executed in order to provide hypothesis explaining these phenomena. Finally based on this analysis different recommendations are provided for future simulations or test benches.