Experimental Studies of Flame Transfer Function in Acoustically Excited Rijke Burners

• Main Authors: Chien - Pang Chen, 陳建邦
• Other Authors: Tzeng - Yuan Chen
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/71484992096415900854

碩士 === 淡江大學 === 航空太空工程學系 === 88 === This research experimentally investigates the flame transfer function in an acoustically excited vertical duct with a laminar premixed flame anchored on a grid located in the lower half of the duct. The experimental configuration is similar to a Rijke tube with three burners of different burner surface acoustic admittances placed separately into one end of the duct. The flame transfer function is determined from the measured acoustic intensity upstream and downstream of the flame zone, which relates both the acoustic velocities and pressures either side of the flame zone. A positive flame transfer function represents that a flame has the possibility to cause a self-excited acoustic oscillation. Results of this research reveal that the flame transfer function is a strong function of the nonreactive acoustic admittance at the flame location. The sign of the flame transfer function is dominated by the location of flame zone on the acoustic field that is also important in the magnitude of flame transfer function. The flame equivalence ratio plays a role mainly in determining the magnitude of the flame transfer function. This study also shows that the characteristic of the flame transfer function could generally be predicted by knowing the imaginary part of nonreactive acoustic admittance at the flame location.