Aerothermal Technologies for Low Emissions Combustors

Abstract

Developments in aeroengine gas turbine combustors have been driven primarily by the pollutant emissions targets set by initiatives such as Flightpath 2050. Technologies to meet these goals are underpinned by research which must increasingly adopt a multidisciplinary/systems approach, accounting for integration/performance matching of combustion system and compressor/turbine turbomachinery. Low emissions lean burn combustors with an increased fraction of compressor efflux through the fuel injector introduce new challenges. Increased size and multi-passage geometries lead to increased complexity of flame-stabilising swirl flow aerodynamics and decreased availability of cooling air. Combustion-induced thermo-acoustics makes all aspects of the combustor acoustic environment important. Illustrations are provided of research into combustor aerothermal technologies being developed to address these problems. For example, the use of a bespoke-design atmospheric isothermal 3D annular test rig allows cost-effective experimental studies of compressor/turbomachinery interactions and arrangements for cooled cooling air architecture. URANS CFD to predict injector acoustic response and LES CFD for high injector aerodynamics and effusion cooling are assessed/validated against representative experimental data.