Experimental research of acoustically perturbed Bunsen flames

• DOI: 10.6100/ir615531
• Publication Date: 2006-01-01
• Authors: Viktor Kornilov
• Keywords: Bunsen burner; Laminar flame speed; Flame speed; Gas burner

This dissertation is related to experimental research of the response Bunsen type laminar premixed methane-air flames an acoustic excitation flow. study stimulated by problem instability burners and combustors used in domestic industrial heating devices where combustion organized via flames. The accordingly can be divided into two parts. first part concentrated on a detailed parametric heat release rate conical tent shaped perturbation gas mixture flow velocity. A Transfer Function (TF) concept which relates (heat oscillation) with stimulus (velocity perturbation) characterize flame’s susceptibility excitation. measurement method based simultaneous registration velocity oscillation hot-wire probe installed burner fresh just upstream flame monitoring OH* radical chemiluminescence flame. influence following parameters TF studied: mean radial profile; equivalence ratio; tube diameter, material opening geometry; confinement co-flow. It shown that gain has complicated jugged form minima maxima. phase constant time delay behavior. An extra term weak frequency dependence found. However, basis data universal phenomenological equation describing proposed. Correlations flame/burner are revealed. Plausible physical mechanisms (hypothesis) formation formulated discussed. second examination origin hypothesis kinematics perturbed visualization measurements. Methods are: Particle Image Velocimetry (PIV), TiO2 smoke tracing, direct front imaging consequent image processing. Accordingly, excited patterns inside cone visualized studied for different frequencies. Convectively traveling jet structures peristaltic In order clarify role motion these specially experiment anchored oscillated holder ring conducted. allows studying both disturbance relation between surface area oscillations. important attachment point’s laborious base zone provides information about anchoring point motion. description results accompanied critical analysis discussion existing theoretical models concepts. As result assessment approaches describe acoustics interaction provided. output summarized way: 132 Summary - parameterization does serve as reference numerical Burners use similar examined purpose using measured presented this dissertation. synthesis well correlations found characteristics formulate consequently check origin. pattern reveal convective structures, back-influence TF. On knowledge received explanation some features practical recommendation deal