过冷沸腾中热声振荡驻波自激形成的实验研究

借助工程信号处理的时域和频域方法，详细分析了竖直管内过冷沸腾中热声振荡特性，获得了热声振荡驻波自激形成与主流过冷度的关系．实验表明，当主流过冷度较大时，过冷沸腾声振荡具有多频性；随着过冷度的下降，多频的声振荡逐渐在管道长度方向上发展为具有单一高频的热声驻波；当过冷度下降到致使加热面接近饱和沸腾时，空泡群脉动所致低频压力波动将取代高频热声振荡驻波．在此基础上，提出了验证热声振荡驻波形成与否的相关判断原则，它可方便地应用于过冷沸腾传热工况的诊断之中．

Experimental Investigation on the Self Excitation of Thermoacoustic Standing Wave in a Vertical Subcooled Boiling Channel

Making use of several methods of signal processing both in time and frequency domains, a detailed survey has been carried out on the characteristics of thermal induced sound oscillation in a vertical subcooled boiling channels. The experiment shows that multifrequency sound vibrations occur in the deeply subcooled boiling cases and that such mutifrequency sound vibrations will spontaneously evolve in the monofrequent and thermoacoustic standing wave in the longitudinal direction of the channels. When the bulk liquid near the heater is close to be saturated, the thermoacooustic standing wave disappears but, instead, a void fluctuation induced pressure wave with very low frequency appears. Based in the relationship between the subcooling of bulk liquid and the properties of thermoacoustic oscillation, a criterion associated with the cross correlation technique had also been proposed in order to identify the occurrence of the thermoacoustic standing wave in a subcooled boiling channels. The criterion is used in the diagnosis of heat transfer status in boiling flows.