Session: 14-03 Turbine Cavities 1

Paper Number: 129257

129257 - The Effect of Rotor Leakage Flows on Hot Gas Ingestion 

In gas turbine engines, the rotor-stator cavities are susceptible to the ingestion of hot gas from the mainstream and must be purged with air bled from the compressor. Accurate prediction of seal performance is needed to design and life the components. At present, there are a variety of methods proposed for solving this problem, but these methods typically lack sensitivity to leakage flows, which are the subject of this work. Recent work has demonstrated that long wavelength circumferential pressure variations, an order of magnitude smaller than those created by vanes and blades, are a mechanism of hot gas ingestion; this paper extends that work to investigate the additional effects of leakage flows. Leakage paths have been introduced into a rotor-stator cavity test facility, which features a double lip rim seal. These leakage paths allow for a variable area leakage through engine-representative inter-platform seals and lock plates. The paper assesses the effect of variations in leakage flow rate on experimentally measured hot gas ingestion through the rim seal. The measurements simulate hot gas ingestion through the dilution of tracer gas. Supplementing the experimental work, a semi-empirical low-order model is shown to be capable of capturing the changes in ingestion with leakage. 

Presenting Author: Nicholas Atkins Cambridge University

Presenting Author Biography: to follow

Authors:

Michael Dawson University of Cambridge
Nicholas Atkins Cambridge University