... and fundamental combustion properties, here ignition delay time and laminar flame speed, were accurately predicted. Through rate of production and sensitivity analyses of the mechanism, nine reactions were identified to have a strong impact on the (over) prediction of the PAHs. These reactions have been modified...

...Daniel Sequera; Ajay K. Agrawal Swirl-stabilized combustion and porous inert medium (PIM) combustion are two methods that have been used extensively, although independently, for flame stabilization. In this study, the two concepts are combined so that the porous insert serves as a passive device...

... used to control the flame temperature (T ad ). For the highest T ad ’s, the combustor is unstable at the first harmonic of the combustor’s natural frequency. As the temperature is reduced, the combustor jumps to fundamental mode and then to a low-frequency mode whose value is well below the combustor’s...

... Numerical Simulation data where the jet is considered to be fuel-rich and the coflow is taken to be fuel-lean. The resulting flame following successful ignition shows the premixed mode of combustion in fuel-rich and fuel-lean zones although an additional diffusion flame branch was also observed...

...Shengrong Zhu; Sumanta Acharya Lean premixed combustion is widely used to achieve a better compromise between nitric oxide (NO x ) emissions and combustion efficiency (related to CO levels). However, combustor operation near the lean blowout (LBO) limit can render the flame unstable and lead...

...Oliver Lammel; Michael Stöhr; Peter Kutne; Claudiu Dem; Wolfgang Meier; Manfred Aigner An experimental analysis of confined premixed turbulent methane/air and hydrogen/air jet flames is presented. A generic lab scale burner for high-velocity preheated jets equipped with an optical combustion...

... framework for combustion simulations as the transient nature of the flow is resolved. In most situations; however, the flame is thinner than the LES grid, and subgrid modeling is required to handle the turbulence-chemistry interaction. Here we examine the predictive capabilities between LES flamelet models...

... of the flame during its upstream motion, tests were done on an atmospheric combustion test rig providing almost complete optical access to the mixing section as well as the flame tube. OH * chemiluminescence, HS-Mie scattering and ionization detectors were applied and undiluted H 2 was used as fuel...

...-excited combustion instabilities with variable fuel components were measured. The mechanisms of coupling between the system acoustic waves and unsteady heat release were investigated. The results show that instability modes and flame characteristics were significantly different with variations in fuel...

... and vapor phase) was imaged. Temperatures were measured with OH-LIF. The burner was designed with a straight outlet to exhibit lifted flames. Hence initial distributions of size, velocity and density of the spray were measured before it entered the flame. Almost complete prevaporization was seen at least...

...Lipika Kabiraj; R. I. Sujith; Pankaj Wahi Bifurcation analysis is performed on experimental data obtained from a simple setup comprising ducted laminar premixed conical flames in order to investigate the features of nonlinear thermoacoustic oscillations. It is observed that as the bifurcation...

... zone makes LP type of combustors a candidate for upstream flame propagation (i.e., flashback) in the premixer that is typically not designed to sustain high temperatures. Moreover, there has been a recent demand for fuel-flexible gas turbines that can operate on hydrogen-enriched fuels like Syngas...

... Modeling of an HCCI Engine Using Model Fuels,” SAE Technical Paper No. 2009-01-0669), we identified some common issues in the predictive nature of the mechanisms that are associated with inadequacies of the core (C 0 -C 4 ) mechanism, such as inaccurate predictions of laminar flame speeds and autoignition...

...Luis Tay-Wo-Chong; Sebastian Bomberg; Ahtsham Ulhaq; Thomas Komarek; Wolfgang Polifke The flame transfer function (FTF) of a premixed swirl burner was identified from a time series generated with computational fluid dynamics simulations of compressible, turbulent, reacting flow at nonadiabatic...

...Daero Joung; Kang Y. Huh; Yunho An This paper describes simulation of a small stationary gas turbine combustor of a reverse flow, semi-silo type for power generation. The premixed coherent flame model (PCFM) is applied for partially premixed methane/air with an imposed downstream flame area density...

... velocities. So far, the flashback data published in literature is based on tube burner experiments with unconfined flames. However, this flame configuration may not be representative for the most critical design case, which is a flame being already present inside the duct geometry. In order to shed light...

...Jacqueline O’Connor; Tim Lieuwen This paper describes an analysis of the unsteady flow field in swirl flames subjected to transverse acoustic waves. This work is motivated by transverse instabilities in annular gas turbine combustors, which are a continuing challenge for both power generation...

...Martin Lauer; Mathieu Zellhuber; Thomas Sattelmayer; Christopher J. Aul Imaging of OH* or CH* chemiluminescence with intensified cameras is often employed for the determination of heat release in premixed flames. Proportionality is commonly assumed, but in the turbulent case this assumption...

...Sage L. Kokjohn; Rolf D. Reitz In this work, a multimode combustion model that combines a comprehensive kinetics scheme for volumetric heat release and a level-set-based model for turbulent flame propagation is applied over the range of engine combustion regimes from non-premixed to premixed...

... on the nonlinear flame response is available. Typically, the flame response shows saturation at high forcing amplitudes. A newly constructed atmospheric test rig, specifically designed for the realization of high excitation amplitudes over a broad frequency range, is used to generate extremely high acoustic...