Abstract
Self-excited noise generation from laminar flames in thin annular jets of premixed methane/air has been investigated experimentally. Various flame shapes were observed in this flow configuration, including conical shaped flames, ring shaped flames, steady crown shaped flames, and oscillating crown shaped flames. Self-excited noise with a total sound pressure level of about 70 dB was generated from the oscillating crown shaped flames for equivalence ratios>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 a function of equivalence ratio and premixture velocity. A frequency doubling phenomenon has also been observed. The measured CH* chemiluminescence data were analysed and which the corresponding sound pressure has been calculated. By comparing the measured and calculated sound pressures, the noise source can be attributed to the flame front fluctuation near the edge of the oscillating crown shaped flames. The flame stability regime was influenced strongly by the mass flow rate of air through the inner tube.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
