The present work addresses unsteady flame dynamics in a lean-premixed swirl-stabilized combustor, with attention focused on the transition of flame structure from a stable to an unstable state. It was found that the inlet temperature and equivalence ratio are the two most important variables determining the stability characteristics of the combustor. A slight increase in the inlet mixture tempe...

A new low-cost optical diagnostic technique, called Cone Beam Tomographic Three Colour Spectrometry (CBT-TCS), has been developed to measure the planar distributions of temperature, soot particle size, and soot volume fraction in a co-flow axi-symmetric laminar diffusion flame. The image of a flame is recorded by a colour camera, and then by using colour interpolation and applying a cone beam t...

Spherical diffusion flames supported on a porous sphere were studied numerically and experimentally. Experiments were performed in 2.2 s and 5.2 s microgravity facilities. Numerical results were obtained from a Chemkin-based program. The program simulates flow from a porous sphere into a quiescent environment, yields both steady-state and transient results, and accounts for optically thick gas-...

We study a thermo-diffusive combustion model for premixed flames propagating in reactive gaseous mixtures which contain inert dust. As observed by Joulin, radiative transfer of heat may significantly enhance the flame temperature and its propagation speed. The Joulin effect is at its most pronounced in the parameter regime where the medium is very transparent while radiative flux dominates conv...

Monocrystalline cubic and/or monoclinic Y2O3:Eu nanoparticles (10-50 nm) were synthesized continuously without post-processing by single-step flame spray pyrolysis (FSP). These particles were characterized by Xray diffraction (XRD), nitrogen adsorption (BET) and transmission electron microscopy (TEM). Photoluminescence (PL) emission was measured as well as the time-resolved PL-intensity decay. ...

The effects of DC electric fields on temperature distributions within pre-mixed propane-air flames have been measured by the technique of thin filament pyrometry (TFP). We have focussed on the dramatic electric-field-induced modifications of the shape and size of the inner cone and the concomitant changes in the temperature profiles of fuel-rich mixtures with equivalence ratios of 1-1.35. Tempe...

in this study, the effect of the levels of hydrogen addition to methane-air premixed flame in a micro-stepped reactor has been studied numerically. in addition, the effects of mixture velocity and walls’ thermal conductivity (kw) on the flame’s location, temperature, and species distribution in a micro reactor were calculated using a 2d numerical laminar steady code. the results showed that an ...

the premixed counterflow flames propagation in combustion of mixture which is a uniform mixture of fuel particles and air is analytically studied. this analysis framework is based on thermal-diffusion model with assumption that the lewis number is unit and the strain rate is constant. velocity profile is assumed as a function of one variable like x. the structure of the flame is presumed to con...

The unresolved Q-branch profiles in the Raman spectra of' nitrogen in premixed, laminar, methane-air, propane-air and butane-air flames with lean to stoichiometric fuel-air equivalence ratios have been recorded experimentally and used to determine flame temperature s with a precision of about 10f0using an iterative computer program which fitted calculated nitrogen spectra to the experimentally ...

Liquid fuels(hydrocarbon and peroxide)are flammableand there is a risk of pool fires during their storage and transportation. In order to measure and develop effective methods for protection and considering safety distances, experimental studies and CFD simulations of pool fire of two hydrocarbon fuels (i.e. gasoline and kerosene) and peroxide (TBPB (tert-butyl peroxybenzoate)) were performed. ...