Self-excited noise generation from laminar methane/air premixed flames in thin annular jets

Kim, Kil-Nam and Joung, Jae-Hoon and Jin, Seong-Ho and Chung, Suk-Ho (2004) Self-excited noise generation from laminar methane/air premixed flames in thin annular jets. In: 2004 Korea-Japan Joint Seminar, December 2004.

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Abstract

Self-excited noise generation from laminar flames in thin annular jets of methane/air premixture has been investigated experimentally. Various flames were observed in this flow configuration, including conical shape flames, ring shape flames, steady crown shape flames, and Oscillating crown shape flames. Self-excited noise with the total sound pressure level of about 70dB was generated from the oscillating crown shape flames for the equivalence ratio larger than 0.95. Sound pressure and CH* chemiluminescence were measured by using a microphone and a
photomultiplier tube. The frequency of generated noise was measured as functions of equivalence ratio and premixture velocity. A frequency doubling phenomena have also been observed. The flame shape during flame oscillation was reconfirmed by a synchronized PIV experiment. The
velocity and pressure field were obtained from PIV. The minimum pressure was formed near the edge of flame representing circulation. By comparing the results of sound pressure, flame luminosity and PIV, the noise source can be attributed to the flame front fluctuation near the edge
of the oscillating crown-shape flames.

Item Type:Conference or Workshop Item (Presentation)
Additional Information:Self-excited noise generation from laminar flames in thin annular jets of methane/air premixture has been investigated experimentally. Various flames were observed in this flow configuration, including conical shape flames, ring shape flames, steady crown shape flames, and Oscillating crown shape flames. Self-excited noise with the total sound pressure level of about 70dB was generated from the oscillating crown shape flames for the equivalence ratio larger than 0.95. Sound pressure and CH* chemiluminescence were measured by using a microphone and a photomultiplier tube. The frequency of generated noise was measured as functions of equivalence ratio and premixture velocity. A frequency doubling phenomena have also been observed. The flame shape during flame oscillation was reconfirmed by a synchronized PIV experiment. The velocity and pressure field were obtained from PIV. The minimum pressure was formed near the edge of flame representing circulation. By comparing the results of sound pressure, flame luminosity and PIV, the noise source can be attributed to the flame front fluctuation near the edge of the oscillating crown-shape flames.
Keywords:Annular jet, Laminar premixed flame, Sound pressure, Flame luminosity, PIV
Subjects:H Engineering > H141 Fluid Mechanics
H Engineering > H340 Acoustics and Vibration
H Engineering > H311 Thermodynamics
Divisions:College of Science > School of Engineering
ID Code:6989
Deposited By: Seong-Ho Jin
Deposited On:30 Nov 2012 09:06
Last Modified:30 Nov 2012 09:07

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