Topic
Diffusion flame
About: Diffusion flame is a research topic. Over the lifetime, 9266 publications have been published within this topic receiving 233522 citations.
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TL;DR: In this paper, a planar laser-induced incandescence (LII) method was used to measure soot volume fraction in a well-characterised, piloted, turbulent non-premixed flame known as the Delft Flame III.
127 citations
01 Jan 2011
TL;DR: In this paper, an experimental investigation of premixed syngas combustion at gas turbine-like conditions, with emphasis on the determination of S T / S L derived as global fuel consumption per unit time.
Abstract: Modifications of conventional natural-gas-fired burners for operation with syngas fuels using lean premixed combustion is challenging due to the different physicochemical properties of the two fuels. A key differentiating parameter is the turbulent flame velocity, S T , commonly expressed as its ratio to the laminar flame speed, S L . This paper reports an experimental investigation of premixed syngas combustion at gas turbine like conditions, with emphasis on the determination of S T / S L derived as global fuel consumption per unit time. Experiments at pressures up to 2.0 MPa, inlet temperatures and velocities up to 773 K and 150 m/s, respectively, and turbulence intensity to laminar flame speed ratios, u ′/ S L , exceeding 100 are presented for the first time. Comparisons between different syngas mixtures and methane clearly show much higher S T / S L for the former fuel. It is shown that S T / S L is strongly dependent on preferential diffusive-thermal (PDT) effects, co-acting with hydrodynamic effects, even for very high u ′/ S L . S T / S L increases with rising hydrogen content in the fuel mixture and with increasing pressure. A correlation for S T / S L valid for all investigated fuel mixtures, including methane, is proposed in terms of turbulence properties (turbulence intensity and integral length scale), combustion properties (laminar flame speed and laminar flame thickness) and operating conditions (pressure and inlet temperature). The correlation captures effects of preferential diffusive-thermal and hydrodynamic instabilities.
126 citations
TL;DR: In this article, the extinction of counterflow diffusion flames of air and methane diluted with nitrogen was studied by drop tower experiments and numerical calculation using detailed chemistry and transport properties, and the mechanism of extinction at low stretch rates was radiative heat loss from the flame zone.
126 citations
TL;DR: In this article, microwave-assisted spark ignition has been used to enhance laminar flame development in a 1.45l constant volume combustion chamber, and microwave enhancement was evaluated on the basis of several parameters including flame development time (FDT), flame rise time (FRT), flame kernel growth rate, flame kernel size, and ignitability limit extension.
126 citations
TL;DR: In this article, a two-dimensional measurement of soot primary particle sizes is obtained in a combustion process from the ratio of emission signals obtained at two delay times after a laser pulse, as the cooling behavior is characteristic of particle size.
126 citations