Amy Lynch

Bio: Amy Lynch is an academic researcher from Air Force Research Laboratory. The author has contributed to research in topics: Combustor & Combustion. The author has an hindex of 12, co-authored 37 publications receiving 577 citations. Previous affiliations of Amy Lynch include University of Dayton Research Institute & Wright-Patterson Air Force Base.

Emissions Characteristics of a Turbine Engine and Research Combustor Burning a Fischer−Tropsch Jet Fuel

Abstract: The emissions characteristics of two combustion platforms, a T63 turboshaft engine and an atmospheric swirl-stabilized research combustor, fueled with conventional military jet fuel (JP-8), a natural-gas-derived Fischer−Tropsch synthetic jet fuel (also referred herein as synjet or FT), and blends of the two were investigated. Nonvolatile particulate matter (PM) and gaseous emissions were analyzed to assess the impacts of the aromatic- and sulfur-free synjet fuel on the combustion products of the two platforms. The engine was operated at two power settings, and the combustor at several equivalence ratios, to evaluate the emission production over a wide range of combustion temperatures. Conventional aerosol instrumentation was used to quantify particle number (PN), size, and PM mass emissions, while a Fourier Transform Infrared analyzer was used to quantify the gaseous species. Planar laser-induced fluorescence and laser-induced incandescence techniques were employed on the research combustor to study the e...

Flame and Flow Topologies in an Annular Swirling Flow

Abstract: This article describes an investigation of flame shapes and flow configurations in a premixed, swirl-stabilized dump combustor. High swirl, annular nozzle flows of this nature enable a variety of different flame configurations and heat release distributions with their associated flow fields. These differences are significant, since each of these configurations, in turn, has different thermoacoustic sensitivities and influences on combustor emissions, nozzle lifetime, and liner heating. These different configurations arise because multiple flame stabilization locations are present, associated with the inner and outer shear layers of the annulus, and the stagnation point of the vortex breakdown region. We present results from high-speed luminosity imaging, particle image velocimetry (PIV), and OH-planar laser induced fluorescence (PLIF) to illustrate time-averaged and instantaneous flame shapes and flow fields associated with the different configuration “families.” Selected cases are compared with large edd...

A Detailed Investigation of Bluff Body Stabilized Flames

Abstract: Abstract : Reduced Order Models (ROMs) and Computational Fluid Dynamics (CFD) codes are tools used to predict the extinction of flames behind bluff bodies. Accurate prediction of these models and codes is predicated on their validation with experimental data. This paper describes detailed experiments to obtain validation data for bluff body stabilized flames over a wide range of conditions. Included are non-reacting data from CFD and LDV, lean blowout and high speed images for three different flame holders. In our previous paper (Kiel 2006) it was asserted that the large vortices were a major driver of extinction. Those assertions are further supported here. It is concluded that the vortex dynamics and not geometry is the dominant mechanism for bluff body flame extinction. This conclusion is supported by the lean blowout data, by the high speed images and reference data from NACA.

A detailed investigation of bluff body stabilized flames (postprint)

Abstract: : Reduced Order Models (ROMs) and Computational Fluid Dynamics (CFD) codes are tools used to predict the extinction of flames behind bluff bodies Accurate prediction of these models and codes is predicated on their validation with experimental data This paper describes detailed experiments to obtain validation data for bluff body stabilized flames over a wide range of conditions Included are non-reacting data from CFD and LDV, lean blowout and high speed images for three different flame holders In our previous paper (Kiel 2006) it was asserted that the large vortices were a major driver of extinction Those assertions are further supported here It is concluded that the vortex dynamics and not geometry is the dominant mechanism for bluff body flame extinction This conclusion is supported by the lean blowout data, by the high speed images and reference data from NACA

Applied Combustion Diagnostics

Abstract: The editors have assembled a world-class group of contributors who address the questions the combustion diagnostic community faces. They are chemists who identify the species to be measured and the interfering substances that may be present; physicists, who push the limits of laser spectroscopy and laser devices and who conceive suitable measuremen

Prediction and control of combustion instabilities in real engines

Abstract: This paper presents recent progress in the field of thermoacoustic combustion instabilities in propulsion engines such as rockets or gas turbines. Combustion instabilities have been studied for more than a century in simple laminar configurations as well as in laboratory-scale turbulent flames. These instabilities are also encountered in real engines but new mechanisms appear in these systems because of obvious differences with academic burners: larger Reynolds numbers, higher pressures and power densities, multiple inlet systems, complex fuels. Other differences are more subtle: real engines often feature specific unstable modes such as azimuthal instabilities in gas turbines or transverse modes in rocket chambers. Hydrodynamic instability modes can also differ as well as the combustion regimes, which can require very different simulation models. The integration of chambers in real engines implies that compressor and turbine impedances control instabilities directly so that the determination of the impedances of turbomachinery elements becomes a key issue. Gathering experimental data on combustion instabilities is difficult in real engines and Large Eddy Simulation (LES) has become a major tool in this field. Recent examples, however, show that LES is not sufficient and that theory, even in these complex systems, plays a major role to understand both experimental and LES results and to identify mitigation techniques.

Aviation gas turbine alternative fuels: A review

Abstract: The development of kerosene-like drop-in alternative aircraft fuels is currently receiving increased attention. Using a range payload approach the need for drop in fuels is justified. The alternative fuels available can be categorised into two groups; depending on whether the product increases supply security of supply or provides a reduced environmental footprint. This paper uncovers this relationship through a review of commercially available process technologies (Transesterfication, Fischer–Tropsch (FT) and hydroprocessing (HRJ)) to produce alternative fuels. The lifecycle assessments available are reviewed to identify what are actually clean fuels or have the potential to be one. A summary of the recent alternative fuel flight test campaigns is given and there results evaluated along with ground based results. A review of combustion characteristics available for the alternative fuels including ignition characteristics are presented to demonstrate the effect the distillation curve has on combustion and how too narrow a distribution of components in the fuel could generate problems with high altitude relight. The effect alternative fuels have on gaseous emissions regulated by the International Civil Aviation Organisation (ICAO) Committee on Aviation Environmental Protection (CAEP) is discussed and shown to be engine hardware dependant. Experimental data, from an Auxiliary Power Unit (APU) engine, are provided showing how, although the Gas to Liquid (GtL) and Coal to Liquid (CtL) FT fuels may not reduce GHG emissions, even with Carbon Capture and Sequestration (CCS), the local air quality around airports will benefit through reduced particulate emissions. Finally the prospects for future fuel development are discussed.