不同狭缝厚度的零质量射流PIV实验研究

为了研究厚度对活塞型激励器产生的零质量射流流场的影响,利用粒子影像测速仪对h=1.5 mm,2mm和3.5 mm三种不同狭缝厚度的零质量射流流场进行了实验研究。采用相位锁定技术,在一个振动周期内捕捉了12个不同相位时刻的流场图片。实验发现,合成射流时间平均流场的横向速度剖面与二维常规射流相似,具有自模化特性;合成射流的质量通量、动量通量、中心线速度的峰值与狭缝厚度成正比。随着狭缝厚度增加,与质量通量和动量通量峰值相应的距出口的无量纲距离减小,而与中心线速度峰值相对应的无量纲距离增加。

Experimental study on orifice depths effect for synthetic jet with Particle image Velocimetry

In order to investigate the effect of depth on the performance of piston-driven synthetic jet,experimental research of three different orifice depths: h=1.5 mm,2 mm and 3.5 mm is presented by means of PIV.During one oscillation cycle 12 images in sequence are captured by phase-locked technique.In the current experiment,the time-averaged cross-stream velocity profiles of synthetic jet show the similarity to the 2D conventional jet.It is found that the peak values of mass flux,momentum flux and centerline velocity of synthetic jet increase in proportion to the depth of orifice.With the increasing of the depth of orifice,dimensionless distance from the stream-wise position of the peak values of mass and momentum flux of the jet to the orifice plane decreases.However,the dimensionless distance corresponding to the maximum centerline velocity increases.