筒形五喷嘴燃烧室冷态时均流场特性实验研究

Experimental study on characteristics of cold time-averaged flow field in a five-nozzle can combustor

关键词:  五喷嘴燃烧室  粒子图像速度仪  入口速度  旋流强度  回流区

Key words:  Five-nozzle combustor  PIV  Inlet velocity  Swirl intensity  Recirculation zone

摘要:

为深入研究五喷嘴燃烧室的流场特性，采用高频PIV测量方法对燃烧室中心截面的冷态流场开展实验研究，主要分析了燃烧室入口速度以及中心喷嘴旋流强度对五喷嘴燃烧室中心截面的时均流场特征的影响。实验结果表明：中心喷嘴和外侧喷嘴出口均存在主回流区，外侧喷嘴与燃烧室壁面间存在角回流区，相邻喷嘴射流相互干涉。喷嘴旋流强度相同时，入口速度由10 m/s增大到20 m/s，中心喷嘴和外侧喷嘴的回流区形态、主回流区长度、最大回流速度位置和气流合并点位置基本不变。入口速度为14.3 m/s时，中心喷嘴旋流强度由0.63增大到0.84，中心喷嘴回流区长度增大，外侧喷嘴回流区长度不变，主回流区最大回流速度显著增大，且更靠近喷嘴出口，气流合并点径向位置基本不变，轴向位置向喷嘴出口移动。

Abstract:

In order to investigate the flow field characteristics of a five-nozzle combustor， the high-frequency PIV experiment was carried out to study the characteristics of the cold flow fields on the central plane of the combustor. Results were mainly focused on the impacts of inlet velocity and central nozzle swirl intensity on time-averaged flow field characteristics of central plane of the five-nozzle combustor. Experimental results indicate the main recirculation zones exist at the outlet of central and outer nozzles， and the corner recirculation zones exist between the outer nozzle and combustor wall. Adjacent swirling flows interact mutually. When swirl intensities of the five nozzles are the same， the shape and length of the main recirculation zones of the central and outer nozzles， the location of maximum reverse velocity and mixing point stay basically unchanged with the inlet velocity increasing from 10 m/s to 20 m/s. When the inlet velocity is 14.3 m/s ，the swirl intensity of the central nozzle increases from 0.63 to 0.84， the length of the main recirculation zone of the central nozzle increases， however， the length of the recirculation zone of the outer nozzle remains unchanged. The maximum reverse velocity of the main recirculation zone increases significantly， and the axial position of the maximum reverse velocity moves upstream to the nozzle outlet. The radial position of the mixing point is basically unchanged， and its axial position moves upstream closer to the nozzle outlet.