射流冲击对短通道出流孔流场影响的实验研究

Experimental investigation of flow fields in outlet hole of a short channel with jet impingement

关键词:  流动分布  流量系数  冲击冷却  速度测量  五孔探针

Key words:  Flow distribution  Flow coefficient  Impingement cooling  Velocity measurement  Five hole probe

摘要:

在有错排射流的短通道内,用五孔针对小长径比、进出口无倒角的直孔内流场进行了详细的测量,着重研究不同通道高度和射流雷诺数对孔内流动规律的影响。实验结果表明:通道高度的变化会显著改变孔内的流场结构,从而影响孔的流量系数;而同一高度比情况下,雷诺数变化的影响则相对较小;孔内流动存在旋涡结构并随通道高度的增大而减弱以至消失,该结果有助于深入了解上游有射流冲击的通道连接段的流动与换热规律。

Abstract:

Experimental investigation was carried out to study the flow fields of the outlet hole in a confined passage with staggered jet impingement arrangement.Detailed flow field measurements were conducted with a five-hole probe.The effect of altering passage height and Reynolds number on the flow field and discharge coefficient of the outlet hole was investigated.Experimental data has shown that the flow behavior and discharge coefficient changed significantly while the passage height to jet hole diameter ratio increased from 1 to 3.Compared with passage height ratio,Reynolds number did not play an important role in the tested range.A strong vortex in the outlet hole was observed at low passage height condition and it was distinctively weakened when the passage height ratio increased to 5,which suggested a flow pattern transformation in the passage.