Erickson, PA
1996
Combustion Characteristics of an Ethanol Spray-Fired Rijke-Tube Combustor in an Actively Controlled Acoustic Field
Dubey, R.K.; Erickson, P.A. and McQuay, M.Q.
HTD-Vol 328, National Heat Transfer Conference, 6:29, 1996. Funded by ACERC.
The combustion characteristics of an ethanol spray flame in a Rijke-tube combustor under the influence of an actively controlled acoustic field has been experimentally investigated using the phase-Doppler particle analyzer technique. The actively controlled acoustic field in the combustor had sound pressure levels of 150 dB and a frequency of 69 Hz. Active control was implemented using a modified fast response feedback loop controller, using two speakers, and was used to attenuate as well as enhance the fundamental mode of oscillation in the combustor. Experiments were performed to study the effect of three sound pressure levels (nonoscillating, oscillating with 150 dB, and enhanced oscillating with 160 dB) on temperature distribution, total heat transfer, Sauter-mean diameter of the ethanol droplets, mean and time-resolved droplet velocity and droplet data rate. The results show that the droplet time-resolved azial velocity component has a preferred frequency equal to the frequency of the sinusoidal pressure wave in the combustor. The maximum temperature measured at quarter length of the combustor increased from 1138 K for nonoscillating to 1194 K for enhanced condition. The heat transferred from the combustor wall by the cooling water increased by 36% of the nonoscillating value for the enhanced condition and was directly dependent on the amplitude of the acoustic field. The Sauter-mean diameter of the spray decreased, on average, 6% and 9% for the sound pressure levels of 150 dB and 160 dB, respectively, while the droplet arrival rate at the prove volume remained the same.
Erickson, PA
1996
Combustion Characteristics of an Ethanol Spray-Fired Rijke-Tube Combustor in an Actively Controlled Acoustic Field
Dubey, R.K.; Erickson, P.A. and McQuay, M.Q.
HTD-Vol 328, National Heat Transfer Conference, 6:29, 1996. Funded by ACERC.
The combustion characteristics of an ethanol spray flame in a Rijke-tube combustor under the influence of an actively controlled acoustic field has been experimentally investigated using the phase-Doppler particle analyzer technique. The actively controlled acoustic field in the combustor had sound pressure levels of 150 dB and a frequency of 69 Hz. Active control was implemented using a modified fast response feedback loop controller, using two speakers, and was used to attenuate as well as enhance the fundamental mode of oscillation in the combustor. Experiments were performed to study the effect of three sound pressure levels (nonoscillating, oscillating with 150 dB, and enhanced oscillating with 160 dB) on temperature distribution, total heat transfer, Sauter-mean diameter of the ethanol droplets, mean and time-resolved droplet velocity and droplet data rate. The results show that the droplet time-resolved azial velocity component has a preferred frequency equal to the frequency of the sinusoidal pressure wave in the combustor. The maximum temperature measured at quarter length of the combustor increased from 1138 K for nonoscillating to 1194 K for enhanced condition. The heat transferred from the combustor wall by the cooling water increased by 36% of the nonoscillating value for the enhanced condition and was directly dependent on the amplitude of the acoustic field. The Sauter-mean diameter of the spray decreased, on average, 6% and 9% for the sound pressure levels of 150 dB and 160 dB, respectively, while the droplet arrival rate at the prove volume remained the same.