Control of burning velocity in premixed burner flame by high-energy electrons of dielectric barrier discharge

Abstract

We activated combustion reactions by superposing a dielectric barrier discharge (DBD) onto a premixed burner flame with CH 4 /O 2 /Ar mixture gas. We observed the shrinkage of the reaction zone by the superposition of DBD. The shrinkage of the reaction zone indicates the enhancement of the burning velocity in the flame. The enhancement of the burning velocity was not caused by thermal effects, since we detected no increase in the gas temperature by the superposition of DBD. On the other hand, we found a unique relationship between the magnitude of the shrinkage of the reaction zone and the optical emission intensity of argon. This experimental result reveals that the enhancement of the burning velocity is determined by the energy and the density of electrons. The superposition of DBD realizes nonequilibrium combustion chemistry in the premixed burner flame, where the energy and the density of electrons are the most important parameters for determining the burning velocity.

Origin of activated combustion in steady-state premixed burner flame with superposition of dielectric barrier discharge

“…However, since the jitter in the discharge current pulse was unavoidable in DBD, the average current waveforms had longer durations, as shown in shows the radial distribution of the gas temperature, which was evaluated by laser Rayleigh scattering as described in a previous paper. 21) The central part of the premixed burner flame was occupied by unburned gas. 32) The unburned gas region had a negligible O density and a low gas temperature close to room temperature.…”

Experimental Investigation of Premixed Methane–Air Combustion Assisted by Alternating-Current Rotating Gliding Arc

“…The shortening of it reflects the enhancement of mixing and turbulent kinetic energy. The diminution of the flame volume can also be interpreted as the shrink of the methane oxidation zone due to the promotion of burning velocity [16]. Both the shortening of jet potential core length and the improvement of burning velocity benefit the flame stabilization.…”

Responses of OH (X2Π) and OH (A2Σ+) to high-energy electrons of dielectric barrier discharge in plasma-assisted burner flame

“…ecently, plasma-assisted combustion 1) has attracted scientific and industrial interest because of its potential in improving speedy-flow combustion, [2][3][4][5][6] stabilizing lean flame, [7][8][9] and increasing burning velocity. [10][11][12][13][14][15] It is expected to be applicable to improved ignition, 16,17) ultralean combustion, 18,19) and the use of alternative fuels. However, our understanding of the microscopic picture of plasma-assisted combustion has remained insufficient to date.…”