Time-varying behaviour of turbulent swirling nonpremixed flames

Journal Article · Sat Jul 15 04:00:00 UTC 2006 · Combustion and Flame

DOI:https://doi.org/10.1016/J.COMBUSTFLAME.2006.03.009· OSTI ID:20829587

Al-Abdeli, Yasir M ^[1]; Masri, Assaad R; Starner, Sten H ^[2]; Marquez, Gabriel R ^[3]

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1. School of Engineering, University of Tasmania, TAS 7001 (Australia)
2. School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, NSW 2006 (Australia)
3. Cordukes Ltd, Industrial Project Division, Silverwater, NSW 2128 (Australia)

This paper presents the results of experimental investigations into the instabilities of turbulent swirling nonpremixed flames. The unconfined flames considered here possess features similar to those found in practical combustors. Extensive time-mean (space-resolved) flow field and composition data already exist in these flames. Results presented herein seek to complement those data with time-resolved measurements acquired using high-speed imaging of laser Mie scattering and shadowgraphs. Mie scattering measurements are designed to identify instabilities specific to the fuel jet that is geometrically centred on the bluff body. Conversely, shadowgraphs reveal the behaviour of the fuel jet as well as a recirculation zone that stagnates on the face of the bluff body. Results from these two imaging techniques are augmented with observations from the frequency spectra of velocity measurements. Overall, the results indicate that two modes of instability exist in these flames: (i) a precession mode in the centre (fuel) jet and (ii) a puffing mode characterised by an expansion and collapse of the toroidal recirculation zone which forms on the face of the bluff body. (author)

• OSTI ID: 20829587
• Journal Information: Combustion and Flame, Journal Name: Combustion and Flame Journal Issue: 1-2 Vol. 146; ISSN CBFMAO; ISSN 0010-2180
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
COMBUSTION INSTABILITY
FLAMES
TIME DEPENDENCE
TURBULENCE