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...

In this short note we propose a new method for construction new nice arrangement on the sphere Sd using the spaces of spherical harmonic.

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, ...

Consider a sequence of point sets on S, where each set X is a spherical ndesign with m points, where m = O(n), and where the spherical distance between points of X is at least λ/ √ m, for some λ common to all sets of the sequence. For each X of such a sequence, the Coulomb energy E(X) is bounded by E(X) 6 1 2 m2 + O(m). The first term and the order of the second term are the same as for the bou...

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...

Final Report: Experimental Studies of Hydrocarbon Flame Phenomena: Enabling Combustion Control Report Title This report summarizes the research accomplished in the project "Experimental Studies of Hydrocarbon Flame Phenomena: Enabling Combustion Control". The main areas of activity are: a) electrostatic flame and flow control, b) flame hysteresis in heated coflows, c) flame lifting and splittin...

This paper offers new insights into a partial fuel stratification (PFS) combustion strategy that has proven to be effective at stabilizing overall lean in direct injection spark ignition engines. To this aim, high spatial and temporal resolution optical diagnostics were applied an optically accessible engine working PFS mode for two fuels different durations of pilot the time spark: 210 µs 330 ...

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...