Acoustic emission measurements for characterizing hydrocarbon/oxygen diffusion flame behavior

Jeffrey D. Moore, Grant A. Risha, Baoqi Zhang, Kenneth K. Kuo

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations

Abstract

An investigation was performed to characterize the behavior of a hydrocarbon/oxygen diffusion flame by acoustic emission measurements. Experiments were performed in a horizontally mounted, 2-D axisymmetric stainless steel chamber with a single shear coaxial injector and an adjustable graphite nozzle at the chamber exit for maintaining a constant chamber pressure. Methane gas flowed through the annular injector port while oxygen exited the center port. Ignition of the diffusion flame was achieved by a C2H 6/O2 torch. Four acoustic transducers placed circumferentially around the diffusion flame at various locations were used in combination with a Pyrex viewing window to observe and classify the diffusion flame as either an anchored flame to the injector, a detached flame with small amplitudes of oscillation, or a near-blowout flame with large amplitudes of oscillation. Results showed that there was a noticeable difference in diffusion flame acoustic emission spectra based on flame stability behavior. Anchored diffusion flames showed no significant trace of acoustic emission at fuel flow rates below 0.65 g/s. Stable, small oscillating detached flames showed minimal amplitude acoustic levels, whereas near-blowout diffusion flames covered a wide range of acoustic frequencies. As the diffusion flame exhibited greater instability behavior, more frequency hits (a measure of the number of times an acoustic signal exceeded a preset threshold) at higher amplitudes were generated until eventual flame blowout occurred. Any increase in the (O/F)mass resulted in an increase in acoustic frequency amplitude and absolute energy. Narrower frequency ranges at higher amplitude values also accompanied this increase in (O/F)mass.

Original languageEnglish (US)
Title of host publicationAdvancements in Energetic Materials and Chemical Propulsion
Pages683-704
Number of pages22
StatePublished - 2005
Event6th International Symposium on Special Topics in Chemical Propulsion: Advancements in Energetic Materials and Chemical Propulsion, ISICP 2006 - Santiago, Chile
Duration: Mar 8 2005Mar 11 2005

Publication series

NameAdvancements in Energetic Materials and Chemical Propulsion

Other

Other6th International Symposium on Special Topics in Chemical Propulsion: Advancements in Energetic Materials and Chemical Propulsion, ISICP 2006
CountryChile
CitySantiago
Period3/8/053/11/05

All Science Journal Classification (ASJC) codes

  • Materials Chemistry

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  • Cite this

    Moore, J. D., Risha, G. A., Zhang, B., & Kuo, K. K. (2005). Acoustic emission measurements for characterizing hydrocarbon/oxygen diffusion flame behavior. In Advancements in Energetic Materials and Chemical Propulsion (pp. 683-704). (Advancements in Energetic Materials and Chemical Propulsion).