不同出口型与驱动频率的活塞型自耦合射流研究  

Experimental investigation of the characteristics of synthetic jet with different orifice aspect ratio and frequency

作　　者：李念[1] 张堃元[1] 沙江[1] 李富[1] 

机构地区：[1]南京航空航天大学能源与动力学院,南京210016

出　　处：《航空动力学报》2007年第3期412-418,共7页Journal of Aerospace Power

基　　金：国家自然科学基金资助(10072027)

摘　　要：采用PIV对驱动频率为10,20,30 Hz的活塞式自耦合射流作动器流场进行测量,应用相位锁定技术,测得了一个周期内72个相位的瞬时流场.对3种频率下的自耦合射流的变化规律的分析,发现当前实验条件下,在几何尺寸不变时,随着频率的增加,冲程长度L0与平均出口速度U0迅速上升;当频率不变时,随着出口孔长宽比AR的增加,冲程长度L0于平均出口速度U0呈下降趋势;而随着孔板厚度d的增加,冲程长度L0却随之下降.通过5个周期360张瞬时流场图的平均得到了自耦合射流的时均流场,数据分析表明,自耦合射流方向性很好,其沿流方向速度剖面具有自模化特征.相对于定常二维平面射流,其稳定发展段中心线上沿流向方向速度衰减较快.By means of experimental investigation of the unsteady flow near the orifice of synthetic jet actuator using PIV technology and using the phase-locked sample technique, 72 instantaneous images and quantitative measurements during one actuating cycle for three different frequencies 10,20,30 Hz are obtained. The PIV measurements rdisplay the properties and structures of the unsteady flow field. Detailed study shows that in the current experiment, with fixed orifice scale and increasing frequency, the corresponding average orifice velocity U0 and stroke length L0 increase. While with constant driving frequency and increasing aspect ratio, both average orifice velocity U0 and stroke length L0 decrease. Also with increasing thickness of the orifice plate d, the friction in the orifice channel increases, consequently the average orifice velocity U0 and stroke length L0 decreases. Time-averaged flow field obtained by 350 image pairs overlapped shows the similarity of dimensionless crossstream velocity profile and the centerline velocity decay ratio of synthetic jet in the fully developed segment is higher than the conventional 2D free jet.

关 键 词：航空 航天推进系统 自耦合射流 PIV技术 相位锁定 

分 类 号：V231.3[航空宇航科学与技术—航空宇航推进理论与工程]