Experimental and Computational Study of Trapped Vortex Combustor Sector Rig with High‐Speed Diffuser Flow

Abstract

The Trapped Vortex Combustor (TVC) potentially offers numerous operational advantages over current production gas turbine engine combustors. These include lower weight, lower pollutant emissions, effective flame stabilization, high combustion efficiency, excellent high altitude relight capability, and operation in the lean burn or RQL modes of combustion. The present work describes the operational principles of the TVC, and extends diffuser velocities toward choked flow and provides system performance data. Performance data include EINOx results for various fuel-air ratios and combustor residence times, combustion efficiency as a function of combustor residence time, and combustor lean blow-out (LBO) performance. Computational fluid dynamics (CFD) simulations using liquid spray droplet evaporation and combustion modeling are performed and related to flow structures observed in photographs of the combustor. The CFD results are used to understand the aerodynamics and combustion features under different fueling conditions. Performance data acquired to date are favorable compared to conventional gas turbine combustors. Further testing over a wider range of fuel-air ratios, fuel flow splits, and pressure ratios is in progress to explore the TVC performance. In addition, alternate configurations for the upstream pressure feed, including bi-pass diffusion schemes, as well as varia-tions on the fuel injection patterns, are currently in test and evaluation phases.

Alternate-Fueled Combustor-Sector Performance—Part A: Combustor Performance and Part B: Combustor Emissions

“…The general description of the combustor and supporting research cell data are similar to those reported in Hendricks et al [4]. The particular aspects of the geometry tested are proprietary and will not be discussed herein.…”

“…Details of the High Pressure Combustion Research Facility at the Air Force Research Laboratory (AFRL) are provided by Shouse et al [1]. Although some general aspects of the fuel delivery system and operations of the facility are similar to those of [1,4], specific facility modifications and increased capability to handle fuel blending had to be made, including remote alternate test fuel storage/tankage and delivery of the alternate test fuel to the facility fuel pumps, flow meters, and control systems (see Appendix B).…”

Experimental and numerical investigations on liner cooling characteristics of a trapped vortex combustor

“…And the assumed PDF (probability density function) model was performed to simulate turbulence-chemistry interactions in turbulent reacting flows. The species include C 12 H 23 (fuel), CH 4 The radiation model was the DO (discrete ordinates) radiation model. It can solve exchange of radiation between gas and particulates.…”

Numerical study of flame/vortex interactions in 2-D Trapped Vortex Combustor

“…In contrast to the conventional combustors, TVC employ cavities placed externally [1] or internally [2] as the flame stabilizer. An optimally designed cavity traps a vortex which is spatially and temporally stable over a wide range of inflow conditions [2].…”