Operation of a Fully Integrated Rotating Detonation Combustor in a T63 Gas Turbine Engine

Abstract The Air Force Research Laboratory (AFRL) has designed a rotating detonation combustor (RDC) as a replacement for the main burner in a T63 gas turbine engine. Unlike the stock combustor, this RDC operates on gaseous hydrogen. Previous AFRL efforts developed a similar RDC but in an open loop configuration. In that configuration, the air and cooling flows were fed from separate external sources and the compressor discharge was diverted and used to estimate compressor work. The focus of that project was to determine the impact of unsteadiness from an RDC on turbine efficiency. Results from the previous project showed that there was minimal impact to turbine efficiency when the detonation outflow was mixed with the cooling flows in a mixer/ejector configuration. The current work is a follow-on effort to design an RDC that operates in a closed loop configuration. Operation and cooling of the RDC is done with the compressor discharge with no external support. The main challenges associated with this effort are designing an RDC that has sufficient performance to close the engine cycle, the ability to work over the entire operating map, and thermal steady state operation. In this work, an RDC is developed that can operate continuously from startup to normal rated power. Results from a 6-minute test are presented where the combustor operates in a deflagrative mode at startup and transitions to detonative combustion as air and fuel flow rates are increased. The combustor was constructed of 304 stainless steel and suffered minor oxidative damage. Results from this work will be applied to a combustor made of Inconel 625 for a future test that is fully integrated in a T63 gas turbine engine.