非对称出口合成双射流激励器矢量特性实验研究

合成双射流(DSJ)激励器由于自身具有独特的矢量控制特性,为合成射流技术应用于主动流动控制提供了新途径。采用了基于射流核心区速度矢量的评价方法,并通过纹影和粒子图像测速法(PIV)流场显示实验研究了非对称出口压电式合成双射流激励器驱动参数(电压和频率)对射流矢量特性的影响。结果表明:合成双射流向出口面积大的一侧偏转,矢量偏转角随电压变化呈现先增大后减小的趋势,存在一个最佳驱动电压幅值,使得矢量偏转角最大;驱动频率变化对矢量偏转角的影响较显著,其对射流矢量的控制机理较复杂,实现矢量偏转角1.53°~36.65°可调,矢量偏转角出现两个峰值,且在振动膜共振频率处,矢量偏转角最小。

Experimental investigation on the vectoring characteristic of dual synthetic jets actuator with asymmetric exits

The unique vectoring characteristic of dual synthetic jets (DSJ) actuator provides a new way for the synthetic jet technology applied to active flow control. The paper employs a new method to evaluate the vectoring angle of dual synthetic jets based on the velocity vectors in the potential core. The effects of driving parameters (driving voltage and frequency) of piezoelectric dual synthetic jets actuator with asymmetric exits are studied using schlieren and particle image velocimetry (PIV) experiments. The results indicate that dual synthetic jets deflects towards the side of slot with larger sectional area. The vectoring angle gradually increases and then rapidly decreases with the variation of the driving voltage. There is an optimal driving voltage at which the vectoring angle reaches a maximum. The effect of the driving frequency on the vectoring angle is remarkable and complicated. The vectoring angle can be adjusted from 1.53°to 36.65°. There are two peaks of the vectoring angle with the variation of the driving frequency. The minimum vectoring angle is attained when the driving frequency approximates the resonance frequency of the vibrating diaphragm.