A thermo-diffusive model has been used to investigate the interaction of non-unity Lewis number and heat loss for laminar premixed flames propagating in a channel. A coordinate system moving with the flame has been used to immobilize the flame within the computational domain. At Lewis numbers significantly below unity in presence of high heat loss, tip opening near the centerline and dead space...

The shapes (flame-sheet and luminous-flame boundaries) of steady nonbuoyant round hydrocarbon-fueled laminar-jet diffusion flames in still and coflowing air were studied both experimentally and theoretically. Flamesheet shapes were measured from photographs using a CH optical filter to distinguish flame-sheet boundaries in the presence of blue CO2 and OH emissions and yellow continuum radiation...

This work focuses upon the effects of DC electric fields on the stability of downward propagating atmospheric pressure premixed propane–air flames under experimental conditions that provide close coupling of the electric field to the flame. With the appropriate electrode geometry, modest applied voltages are shown to drive a stable conical flame first into a wrinkled-laminar flamelet geometry, ...

Premixed methane-air mixture is introduced at the center of two parallel circular quartz plates separated by a millimeter scale distance (<or= 5mm). Two plates are heated with an external heater to create a positive temperature gradient condition along the flow direction. The combustion characteristics of lean methane-air mixtures are investigated at phi=0.67 and phi=0.85 in the laminar flow re...

The atomic absorption of aluminum with air-acetylene flame was interfered by the formation of involatile compounds in the flame. Amines promoted the atomization of aluminum in the flame. Aluminum could be determined by atomic absorption spectrometry with an air-acetylene flame. The absorption of aluminum increased and then attained a constant value as the concentration of amines increased. The ...

Microscopic turbulence-flame interactions of thermonuclear fusion flames occuring in Type Ia Supernovae were studied by means of incompressible direct numerical simulations with a highly simplified flame description. The flame is treated as a single diffusive scalar field with a nonlinear source term. It is characterized by its Prandtl number, Pr ≪ 1, and laminar flame speed, SL. We find that i...

Shock wave/fire interactions initiated by high explosives have been historically demonstrated as potentially effective ways to control oil well fires or even forest fires in situations where conventional means cannot be applied. However, the mechanisms by which a fire can be extinguished by a shock wave are not well understood. A series of experiments have been conducted involving a moving shoc...

A swirling CH4/air diffusion flame at atmospheric pressure was stabilized in a gas turbine model combustor with good optical access. The investigated flame with a thermal power of 10 kW and an overall equivalence ratio of 0.75 exhibited pronounced thermoacoustic oscillations at a frequency of 295 Hz. The main goal of the presented work was a detailed experimental characterization of the flame b...

Due to the ever wider use of composite materials within aerospace applications, fireproof tests get recently an increased attention. Numerical simulation is expected in the coming years to accompany engineers in their design work to increase the chance of success in the fireproof certification tests. The current research focuses on the numerical investigation of a premixed methane-air flame imp...