应用PIV技术测量压电型自耦合射流  

Experiments on the Characteristics and Structure of Unsteady Flow Field of Synth etic Jet

作　　者：李念[1] 张堃元[1] 沙江[1] 

机构地区：[1]南京航空航天大学能源与动力学院,江苏南京210016

出　　处：《航空学报》2007年第1期20-24,160,共6页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(10072027)

摘　　要：采用PIV对激励信号频率为300Hz、400Hz和500Hz的矩型出口自耦合射流流场进行测量,应用相位锁定技术,测得一个激励周期内12个相位的瞬时流场,并由120张瞬时流场图像的平均得到了射流流场时均流动特性。分析了3种频率下的流场结构,发现在当前实验条件下,射流的扩张半角近35°,稳定增长区的中心线速度随流向距离的-0.511次方变化。当频率为f=400Hz时流量增长率高达4,动量增长率最高达4.5。当沿流向距离y/h>40后自耦合射流的动量呈下降趋势,这与定常二维平面射流动量保持不变的规律不同。Experimental investigation on the unsteady flow near the slot of synthetic jet actuator using PIV technology,and with the phase-locked sample technique instantaneous images and quantitative measurements results during one actuating cycle for three different frequencies 300 Hz,400 Hz and 500 Hz is presented,and ensemble-averaging of 120 image pairs as well. The PIV measurement results indicate the properties and structures of the unsteady flow field. Detailed study shows that in the current experiment the half overspreading angle of the jet is nearly 35° and in the far field,the synthetic jet is similar to the conventional 2D jets. However, compared to the conventional 2D jets, the streamwise decrease of time-averaged centerline velocity is somewhat higher （～x 0.511 ）. Especially for f=400 Hz the volume flow rate ratio is nearly 4.0 and its top value of momentum flux ratio is higher than 4. 5. For flow field y/h〉40, the departure from the conventional 2D jet is consistent with the streamwise decrease in the jet＇s momentum flux as a result of a low pressure region near the slot.

关 键 词：PIV粒子图像测速仪 自耦合射流 涡对 非定常流动 

分 类 号：V211.3[航空宇航科学与技术—航空宇航推进理论与工程]