Back to Search
Start Over
Electroacoustic control of Rijke tube instability
- Source :
- Scopus-Elsevier
- Publication Year :
- 2017
- Publisher :
- Elsevier BV, 2017.
-
Abstract
- Unsteady heat release coupled with pressure fluctuation triggers the thermoacoustic instability which may damage a combustion chamber severely. This study demonstrates an electroacoustic control approach of suppressing the thermoacoustic instability in a Rijke tube by altering the wall boundary condition. An electrically shunted loudspeaker driver device is connected as a side-branch to the main tube via a small aperture. Tests in an impedance tube show that this device has sound absorption coefficient up to 40% under normal incidence from 100 Hz to 400 Hz, namely over two octaves. Experimental result demonstrates that such a broadband acoustic performance can effectively eliminate the Rijke-tube instability from 94 Hz to 378 Hz (when the tube length varies from 1.8 m to 0.9 m, the first mode frequency for the former is 94 Hz and the second mode frequency for the latter is 378 Hz). Theoretical investigation reveals that the devices act as a damper draining out sound energy through a tiny hole to eliminate the instability. Finally, it is also estimated based on the experimental data that small amount of sound energy is actually absorbed when the system undergoes a transition from the unstable to stable state if the contrpaol is activated. When the system is actually stabilized, no sound is radiated so no sound energy needs to be absorbed by the control device.
- Subjects :
- Physics
Acoustics and Ultrasonics
Mechanical Engineering
Acoustics
Condensed Matter Physics
01 natural sciences
Instability
010305 fluids & plasmas
Damper
Noise reduction coefficient
Mechanics of Materials
0103 physical sciences
Sound energy
Rijke tube
Tube (fluid conveyance)
Boundary value problem
Loudspeaker
010301 acoustics
Subjects
Details
- ISSN :
- 0022460X
- Volume :
- 409
- Database :
- OpenAIRE
- Journal :
- Journal of Sound and Vibration
- Accession number :
- edsair.doi.dedup.....2a068176247f63e026537ba388e42754