Annular Dump Diffuser and Deswirl System for Back-Pressure Control in Engine-Scale Transonic Annular Cascade

Abstract A common requirement for turbomachinery testing facilities is the ability to independently control Mach number and Reynolds number. In practice, this means independent of inlet total pressure exit static in a test facility. paper, we present solution problem with particular applicability large-scale annular facilities. We describe design commissioning combined dump diffuser deswirl system back-pressure environments high-whirl transonic flow. The application was an cascade nozzle guide vanes from current civil engine. purpose provide number, by controlling intermediate plenum which forms diffuser. necessary facilitate optical probe access (without interaction effects) reduce risk disturbances (due duct design). has been installed validated engine component aerothermal (ECAT) facility at University Oxford. implementation system, flow passes through short, parallel duct, dumped into plenum, before being re-accelerated vane ring. ring turns axial direction. then discharged variable choke plate silencer. Conditioning have zero whirl reduces sensitivity effective blockage angle. design, aerodynamic performance, overall performance are assessed detailed experiments 3D unsteady computational fluid dynamics predictions. notoriously challenging, exhaust conditioning applications including rocket turbo-pump systems.