旋流器后火焰流场的试验研究

AN EXPERIMENTAL STUDY ON REACTING FLOW FIELD BEHIND A SWIRLER

本文给出了用LDA测量旋流器后火焰流场的试验研究结果。试验表明,中心开孔的平底碟形火焰稳定器后方形成双回流区,湍流脉动的均方根速度在回流区边界区域上发生突变,且湍流脉动速度的概率密度分布图上存在双峰;用热电偶测出的温度分布表明内外两支火焰在双回流区的内外边界附近开始,并向下游伸展。试验结果为应用旋流器燃烧室性能改进提供了依据,也为发展带回流的湍流反应流数值计算方法提供了验证依据。

The results of experimental study on reacting flow behind a swirler by LDA are presented in this paper. The experiments show that there exists a twin recircu-lation zone behind the cup shaped swirler with a hole in the middle of its plain bottom, and sudden changes in turbulent fluctuation velocity occur in the boundary region of the recirculation zones, and also there appear two peaks in the profile of probability density function of the fluctuation velocity in that zones. The temperature profiles obtained by thermocouple show that there exist two branches of flame,outer and inner flames, starting and spreading downstream from the outside and inside boundaries of the twin recircu-lation zone. The experiment results may be used as a basis to improve the performance of a combustor with swirler, and also to develop the numerical method for turbulent reacting flow with recirculation.