In this work, we consider hydrodynamic problems with cold flame propagation by merging a second-order projection method for viscous Navier-Stokes equations with modern techniques for computing the motion of interfaces propagating with curvature-dependent speeds. This is part of our efforts to try and approximate the solution of a simplified model of turbulent combustion. Results are given for a...

The study of premixed laminar flames is a central question in combustion theory. Here the differential equations describing steady flame propagation are investigated mathematically. The emphasis is on analytic results, hence a simple model, a onestep exothermic reaction with linear or radiative heat loss is studied. The equations governing our model can be considered as travelling wave equation...

the flame propagation through a coal dust-air mixture in a spherical vessel was studied by means of a one-dimensional, arrhenius-type kinetics and quasi-steady model. the model includes the evaporation of the volatile matter of dust particles into a known gaseous fuel (methane) and the single-stage reaction of the gas-phase combustion. effect of venting devices as safety idea and the radiation ...

The propagation of turbulent premixed flames influenced by the intrinsic hydrodynamic flame instability (the Darrieus-Landau instability) is considered in a two-dimensional case using the model nonlinear equation proposed recently by Bychkov [Phys. Rev. Lett. 84, 6122 (2000)]. The nonlinear equation takes into account both the influence of external turbulence and the intrinsic properties of a f...

A situation in which a diffusion flame reaches an end at some position in a medium of non-premixed reactants is studied. The mixing of reactants that takes place ahead of the diffusion flame leads to the formation of a "triple-flame", a structure which consists of a fuel-rich premixed flame, a fuel-lean premixed flame. and a diffusion flame that starts where the two premixed flames meet. An imp...

This paper reports an experimental investigation of premixed propane and methane-air flames propagating freely in tubes 1.5 m long and with diameters 54 and 94 mm. Two regimes of propagation are distinguished by correlating the flame speed and the radius of curvature at the flame tip. The characteristic lengths are then related to the cut-off wavelengths estimated from linear theories and compa...

In a recent numerical paper (Nicoli et al. Combust. Sci. Technol. vol. 186, pp. 103-119; 2014) [1], a model of isobaric flame propagation in lean sprays has been proposed. The initial state of the monodisperse mists was schematized by a system of individual alkane droplets initially located at the nodes of a facecentered 2D-lattice, surrounded by a saturated mixture of alkane and air. In the pr...

Quasi-steady and unsteady propagations of methane and propane–air premixed flames in a mesoscale divergent channel were investigated experimentally and theoretically. The emphasis was the impact of variable cross-section area and the flame-wall coupling on the flame transition between different regimes and the onset of flame instability. Experimentally, for the first time, spinning flames were ...

An experimental and theoretical investigation of free turbulent premixed flames propagating in isotropic turbulence at neutrally stable preferential diffusion conditions is described. Experiments were limited to the wrinkled thin laminar ftamelet regime and involved mixtures of hydrogen, air, and nitrogen ignited within a fan-stirred combustion chamber. Measurements included flame tomography fo...

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...