The Application of Fluidic Sealing in Shrouded Gas Turbine Blades

Abstract

This paper presents a study conducted on a new gas turbine designed to limit leakage in the labyrinth seal. The slots in the fin are used to generate a bypass flow, which obstructs the flow in the gap above the fin. The method was tested numerically and experimentally beforehand using a simplified model without rotation or blade passages. In this paper, the validation of the method using a model of a turbine stage is shown. Reynolds-averaged Navier–Stokes simulations using two turbulence models—Spalart–Allmaras (SA) and k-ω EARSM—were conducted. Comparisons of leakage flow and stage efficiency for reference and fluidic sealing configurations are presented. Fluidic sealing configuration is effective and reduces the leakage flow by 13–18.5% (depending on the turbulence model). The analysis of the flow structure in the seal region revealed that the use of fluidic sealing resulted in significant circumferential flow anisotropy.