WR-21 is an intercooled and recuperated (ICR) gas turbine engine being developed by the U. S. Navy (USN) with contributions from the Royal Navy and the French Navy. A key component of the WR-21 engine is the recuperator used to recover waste heat from engine exhaust gas. The recuperator is being designed and fabricated by AlliedSignal Aerospace Company under subcontract to Northrop Grumman Marine Services, the prime contractor for the WR-21 gas turbine engine. One of the most challenging developmental items for the WR-21 engine has proven to be the recuperator. This paper discusses the development of the recuperator, including the advanced development (AD) recuperator which failed after a few hours of operation, the limited operating unit (LOU) recuperator which has supported much of the WR-21 engine development testing and the engineering development model (EDM) recuperator which will be used for a 3000 hour engine endurance test. Included is an overview of USN technical requirements for the recuperator and a review of operating experience with the AD and LOU recuperators. Failure modes that have been experienced are discussed in detail, including root cause evaluations and design modifications. Steps taken to extend the life of the LOU recuperator are discussed. In addition, testing (both single core and full size recuperator) and analytical models that have been used to improve the design and reliability of the recuperator are addressed.
Characterization of stress-strain state in gas turbine engine compressor disc taking into account damage accumulation
