Investigation of rim seal exchange and coolant re-ingestion in rotor stator cavities using gas concentration techniques

摘要

Gas turbine engine performance requires effective and reliable internal cooling over theudduty cycle of the engine. Understanding the effectiveness of cooling flows when makingudlife predictions for rotating components subject to the main gas path temperatures isudcrucial. A test facility has been developed at the University of Sussex incorporating audtwo stage turbine designed to support a European funded research project with theudobjective of enhancing the understanding of interactions between main annulus gasudpaths and secondary air systems. This thesis describes the specific contribution of theudauthor to the research conducted at the test facility.ududNon-invasive gas seeding and concentration measurement techniques together with hotudgeometry displacement measurements have been developed to meet three distinctudobjectives: to determine inter-stage seal flows between rotor disc cavities; to provideuddata to quantify rim seal exchange flows between rotor stator cavities and the mainudannulus gas path for both bulk ingestion and egress conditions; and, to provide data toudquantify the re-ingestion of cooling air egressed into the main annulus gas path.udDetailed knowledge of these flows is vital to understanding the flow structures withinudrotor stator cavities and to optimise coolant delivery methods.ududExperimental results are presented for a number of cooling flow supply geometries andudflow rates. The gas concentration measurement techniques developed and the resultsudobtained are compared to traditional measurements as well as numerical simulationsudcarried out by research project partners. This work develops the measurementudtechniques of rotor stator cavity flows and provides data suitable for the validation ofudimproved thermo-mechanical and CFD codes, beneficial to the engine design process.