Lean-Burn Combustor Simulator for an Engine-Component Test Facility: An Experimental and Computational Study

Abstract

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.

Unsteady Flows and Component Interaction in Turbomachinery

“…A generally good agreement was found between the experimental results and the URANS data available from the design phase, thus confirming that URANS was a valid tool for combustor simulator preliminary design. Recently, the original design [85,86] was modified and scaled by Amend et al [160] for compatibility with the high-pressure operating conditions of the Engine Component Aerothermal Facility (ECAT) [161]. Numerical simulations were performed using different turbulence closures (namely k − ϵ [162], k − ω SST [163], and SSG RSM [164]) that demonstrated sufficient accuracy in the evaluation of flow profiles at the reporting plane without the vane when compared with the available experimental data, especially considering the k − ϵ model.…”

“…WCTF (Warm Core Turbine Facility) [181,182] LSRR (Large Scale Rotating Rig) [183] TATEF (Turbine Aero-Thermal External Flows) & TATEF2 [34,37,38,184] RTBDF at Gas Turbine Laboratory (MIT, Cambridge, MA, USA) [185] TRF (Turbine Research Facility) at Air Force Research Laboratory (AFRL) [53,186] SILOET (Strategic Investment in Low-carbon Engine Technology) [19] TTF (Turbine Test Facility) [55,187] LEMCOTEC (Low Emissions Core-Engine Technologies) [87,188] OTRF (Oxford Turbine Research Facility) [85,86] FACTOR (Full Aerothermal Combustor-Turbine interactiOns Research) [91,[165][166][167][168] ECAT (Engine Component Aerothermal Facility) [160,161] STech (Smart Turbine Technologies) [79] Most of the temperature distortions were in the range 0.73 < T/T < 1.21 except the LSRR case, which was characterized by a wider temperature interval 0.68 < T/T < 2.0. Among the listed ones, the most recent facilities were also the more representative of modern lean-burn combustors.…”