Mechanical vibrations introduced in diffusion flame burners significantly affect the flame characteristics. In this experimental study, the effects of axial vibrations on the characteristics of laminar diffusion flames are investigated systematically. The effect of the frequency and amplitude of the vibrations on the flame height oscillations and flame stability is brought out. The amplitude of flame height oscillations is found to increase with increase in both frequency and amplitude of burner vibrations. Vibrations are shown to enhance stability of diffusion flames. Although flame lifts-off sooner with vibrations, stability of the flame increases.

Vasudevan Raghavan

Department of Mechanical Engineering

K. Srinivasan

AXIAL VIBRATIONS

Diffusion Flame

Experimental studies

Flame characteristics

FLAME HEIGHT

Flame stability

LAMINAR DIFFUSION FLAMES

Low frequency

Diffusion

Vibrations (mechanical)

Fulltext

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Effect of low frequency burner vibrations on the characteristics of jet diffusion flames

International Journal of Spray and Combustion Dynamics

In this work, effects of burner configurations on the natural oscillations of methane laminar diffusion flames under atmospheric pressure and normal gravity conditions have been studied experimentally. Three regimes of laminar diffusion flames, namely, steady, intermittent flickering and continuous flickering have been investigated. Burner configurations such as straight pipe, contoured nozzle and that having an orifice plate at the exit have been considered. All burners have the same area of cross section at the exit and same burner lip thickness. Flame height data has been extracted from direct flame video using MATLAB. Shadowgraph videos have been captured to analyze the plume width characteristics. Results show that, the oscillation characteristics of the orifice burner is significantly different from the other two burners; orifice burner produces a shorter flame and wider thermal plume width in the steady flame regime and the onset of the oscillation/flickering regimes for the orifice burner occurs at a higher fuel flow rate. In the natural flickering regime, the dominating frequency of flame flickering remains within a small range, 12.5 Hz to 15 Hz, for all the burners and for all fuel flow rates. The timeaveraged flame length-scale parameters, such as the maximum and the minimum flame heights, increase with respect to the fuel flow rate, however, the difference in the maximum and the minimum flame heights remains almost constant.

Effects of burner configurations on the natural oscillation characteristics of laminar jet diffusion flames

Mechanical vibrations in a burner are found to affect the characteristics of premixed flames. In the present experimental investigation, the effects of axial vibrations of a tubular burner on the characteristics of laminar premixed methane-air flames are investigated. The effect of the frequency and amplitude of the burner vibrations on the flame height oscillations are studied. At a low frequency of around 10 Hz, no effect of vibrations on flame characteristics is observed. At frequencies higher than 10 Hz, the amplitude of flame height oscillations is found to increase with increase in both frequency and amplitude of burner vibrations for the range of frequencies and amplitudes considered.

Effect of low frequency burner vibrations on the characteristics of premixed flames

Dynamic Characterization of Candle Flame

Flow, Turbulence and Combustion

Behavior of Moderately Oscillating Sooting Methane-Air Diffusion Flames

Proceedings of the Combustion Institute

Computational and experimental study of a forced, time-dependent, methane–air coflow diffusion flame

Progress in Energy and Combustion Science

Impacts of a jet's exit flow pattern on mixing and combustion performance

Combustion and Flame

Hydroxyl time-series measurements and simulations for turbulent premixed jet flames in the thickened preheat regime

Effect of low frequency burner vibrations on the characteristics of jet

Journal	International Journal of Spray and Combustion Dynamics
ISSN	17568277
Open Access	Yes