Large-eddy simulation of premixed combustion is a computational challenge, because complex diffusion and reaction processes often occur in very thin layers. The interaction of these processes with turbulence determines the main properties of the flame brush, such as its burning velocity or its thickness. In turbulent flows, the large vortices wrinkle the flame brush and increase its surface, wh...

The LES method is an attractive approach for the simulation of turbulent jet flames. In this method, the effects of large scale structures controlling the mixing process are resolved while small-scale effects such as the leading-edge flames involved in the flame base dynamics are accounted for by the subgrid-scale models. The LES approach is examined in this study with a particular emphasis on ...

New combustion systems based on ultra-lean premixed combustion have the potential for dramatically reducing pollutant emissions in transportation systems, heat, and stationary power generation. However, lean premixed flames are highly susceptible to fluiddynamical combustion instabilities, making robust and reliable systems difficult to design. Lowswirl burners are emerging as an important tech...

Critically understanding the ‘standard candle’-like behavior of Type Ia supernovae requires understanding their explosion mechanism. One family of models for Type Ia Supernovae begins with a deflagration in a Carbon-Oxygen white dwarf which greatly accelerates through wrinkling and flame instabilities. While the planar speed and behavior of astrophysically-relevant flames is increasingly well u...

Nonpremixed turbulent reacting flows are intrinsically difficult to model due to the strong coupling between turbulent motions and reaction. The large amount of heat released by a typical hydrocarbon flame leads to significant modifications of the thermodynamic variables and the molecular transport coefficients and thus alters the fluid dynamics [1],[4]. Additionally, in nonpremixed combustion,...

A nonlinear equation describing curved stationary flames with arbitrary gas expansion θ = ρfuel/ρburnt, subject to the Landau-Darrieus instability, is obtained in a closed form without an assumption of weak nonlinearity. It is proved that in the scope of the asymptotic expansion for θ → 1, the new equation gives the true solution to the problem of stationary flame propagation with the accuracy ...

This paper reports for the first time a planarised optical fiber composite formed using Flame Hydrolysis Deposition (FHD). As a way of format demonstration a Micro-Opto-Electro-Mechanical (MOEMS) hot wire anemometer is formed using micro-fabrication processing. The planarised device is rigidly secured to a silicon wafer using optical quality doped silica that has been deposited using flame hydr...

To better understand the combustion chemistry of tetrahydrofuran (THF) and 2-methyltetrahydrofuran (MTHF) which has been considered as promising bio-fuel, the structure of their stoichiometric (φ=1.0) low-pressure laminar premixed flame has been investigated. The flames have been stabilized on a burner at a pressure of 50 Torr (6.7 kPa) using argon as dilutant (78 %), with a gas velocity at the...

This work presents recent measurements of a CH4/H2/N2 turbulent nonpremixed jet flame using an imaging Fourier-transform spectrometer (IFTS). Spatially resolved (128×192 pixels, 0.72  mm/pixel) mean radiance spectra were collected between 1800  cm(-1)≤ν˜≤4500  cm(-1) (2.22  μm≤λ≤5.55  μm) at moderate spectral resolution (δν=16  cm(-1), δλ=20  nm) spanning the visible flame. Higher spectral-reso...