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实验研究了由导向叶片引起的环形旋转冲击射流的流动与传热特性,并与传统环形冲击射流进行了比较.采用粒子图像测速法观察了不同冲击距离下两种射流的出口流动结构;测量并对比了两种射流在均匀加热冲击靶板上的局部压力及传热分布.对于环形冲击射流,所测得的流动结构、壁面压力及传热分布与公开数据一致;在足够大的冲击距离下,该射流显示出类似于单个圆管冲击射流的特征.对于环形旋转冲击射流,在中小冲击距离下,局部压力和传热系数在冲击靶板上的分布与传统环形冲击射流相比更不均匀,但总体传热性能更好,这是由于漩涡在导向叶片下游脱落、对流所致;在较大的冲击距离下,环形旋转射流未显示出类似于单个圆管冲击射流的特征,且由于高动量耗损,其传热性能低于传统环形射流.
The flow and heat transfer characteristics of circular jet impingement jet induced by guide vanes were experimentally studied and compared with the conventional annular impinging jet.The particle jet velocity was used to observe the outlet flow structures of the two jets at different impingement distances. The local pressure and heat transfer distribution of the two jets on the uniformly heated target plate were compared. For the annular jets, the measured flow structure, wall pressure and heat transfer distribution are consistent with the published data. At sufficiently large impact distances , The jet shows a characteristic similar to that of a single tube impingement jet.For annular rotary impinging jets the distribution of local pressure and heat transfer coefficient on the impinging target plate is less uniform at medium and small impingement jets than conventional annular impinging jets , But the overall heat transfer performance is better because the vortex sheds and convects downstream of the guide vanes. At larger impact distances, the annular swirling jet does not show characteristics similar to a single tube impinging jet, and due to the high Momentum loss, the heat transfer performance is lower than the traditional circular jet.