Compressible direct numerical simulation of low-pressure turbines: Part I - Methodology

Abstract

Modern low pressure turbines (LPT) feature high pressure ratios and moderate Mach and Reynolds numbers, increasing the possibility of laminar boundary-layer separation on the blades. Upstream disturbances including background turbulence and in- coming wakes have a profound effect on the behavior of sepa- ration bubbles and the type/location of laminar-turbulent transi- Tion and therefore need to be considered in LPT design. URANS are often found inadequate to resolve the complex wake dynam- ics and impact of these environmental parameters on the bound- Ary layers and may not drive the design to the best aerodynamic efficiency. LES can partly improve the accuracy, but has diffi- culties in pr..