LEAN-BURN COMBUSTOR SIMULATOR FOR AN ENGINE-COMPONENT TEST FACILITY: AN EXPERIMENTAL AND COMPUTATIONAL STUDY


 The computational and experimental assessment of a lean-burn low-NOx combustor simulator for an engine component test facility is presented. The Engine Component Aero-Thermal (ECAT) facility is a full-scale engine-parts facility, designed for the study of the aero-thermal performance of fully cooled high-pressure nozzle guide vanes (NGVs). The facility operates with non-dimensionally matched engine conditions in terms of Reynolds number, Mach number and coolant-to-mainstream pressure ratio. The combustor simulator is designed to replicate lean-burn conditions of swirl and temperature distortion upstream of the nozzle guide vanes. The purpose is to allow the study of flow capacity, aerodynamic performance (with film cooling), and thermal performance (overall effectiveness) in the presence of engine-realistic inlet distortions. Detailed experimental measurements with multi-hole probes and thermocouples are presented and compared to results from RANS Simulations. Additional simulations were performed to understand how the elevated back pressure and vane potential field affect the non-dimensional profiles of pressure loss, residual swirl and temperature at the combustor-turbine interface. This is perhaps the most comprehensive study to date of a combustor simulator in an engine-scale research facility, providing unique insight into the known challenges of simulator design, scaling issues when moving from low to high Reynolds number, and limitations of CFD in this flow environment.