The effects of a gas explosion in enclosures like vessels can be limited e.g. by gas explosion venting systems. The major design step of this constructive explosion protection method is to determine the required vent area, which depends significantly on whether turbulent combustion exists. However, current standards like NFPA 68 or EN 14994 are applicable only to limited boundary conditions and...

This preliminary study presents a new method for the determination of dissolved gases in sea-water. After headspace extraction, gaseous compounds are separated by GC on a dual column adsorption system. The individual species are thereafter eluted to three different detectors (thermal conductivity, flame ionization and FPD) using a second switching valve. The analysis is quantitative for methane...

We discuss recent developments in the application of high-order adaptive mesh refinement constructions in reacting flow computations. We present results pertaining to the time integration of coupled diffusive-convective terms in this context using a stabilized explicit Runge-Kutta-Chebyshev scheme. We also discuss chemical model reduction strategies, with a focus on the utilization of computati...

An all-diode-pumped, multistage Nd:YAG amplifier is investigated as a means of extending the duration of high-power, burst-mode laser pulse sequences to an unprecedented 30 ms or more. The laser generates 120 mJ per pulse at 1064.3 nm with a repetition rate of 10 kHz, which is sufficient for a wide range of planar laser diagnostics based on fluorescence, Raman scattering, and Rayleigh scatterin...

The asymptotic structure of unstrained, laminar, fuel-rich, premixed methane flame is analyzed by using a reduced chemical-kinetic mechanism made up of three global steps. Analysis is carried out for values of equivalence ratio greater than 1.3. The flame structure is presumed to comprise three zones: an inert preheat zone, a thin reaction zone, and a post-flame zone. In contrast to previous as...

A supersonic combustor was experimentally investigated using both conventional instrumentation and laser-based diagnostics. Planar laser-induced fluorescence (PLIF) imaging of OH was used in the main section of the combustor to examine flameholding and flame propagation during a series of evaluations at conditions simulating Mach-5.5 flight. Parameters of interest in this study included the ang...

Raman scattering from nitrogen in laminar (Re 4 1600) and turbulent (Re 4 15,000) non-premixed flames of diluted methane has been investigated as a means of complementing the two-scalar mixturefraction computation based on measurements of fuel mass fraction and temperature (nFT). Using a diluent consisting of argon and oxygen with an overall volumetric dilution ratio of 3/1 (diluent/fuel) allow...

Progress toward extraction of the elusive pressure-densitycorrelation in variable density reacting flows is reported uponin this paper, using a premixed methane—air flame in open sur-roundings as the test medium. The relationship between den-sity and other scalars is shown. Molecular Rayleigh scattering,laser Doppler velocimetry, and dynamic Pitot barometry are theexperi...

Achieving understanding through combustion modeling is limited by the ability to recognize the implications of what has been computed and to draw conclusions about the elementary steps underlying the reaction mechanism. This difficulty can be overcome in part by making better use of reaction path analysis in the context of multidimensional flame simulations. Following a survey of current practi...

The thermal environment in small and moderate-scale pool flames is studied by Large Eddy Simulation and the Finite Volume Method for radiative transport. The spectral dependence of the local absorption coefficient is represented using a simple wide band model. The predicted radiative heat fluxes from methane/natural gas flames as well as methanol pool burning rates and flame temperatures are co...