合成射流用于提高微型飞行器翼型气动特性的研究

合成射流激励器可微型化，能够在流场局部实施细致的流动控制.提出将合成射流技术用于NACA0012翼型绕流的主动流动控制,在SIAMM400低速低湍流风洞中对该翼型绕流流场进行烟线显示实验、PIV测量实验及翼型表面压力测量实验，并与数值模拟结果相比较.结果表明：（1） 在来流雷诺数为18 000，翼型攻角小于15°时，合成射流能有效减小翼型表面附近的分离区大小；（2） 在翼型攻角 0°~ 15°范围内，不同攻角下需要调节最佳射流激励频率.如攻角为2.5°时，合适的激励器频率为1 300 Hz；攻角5°时，400 Hz和1 300 Hz比较适合；而攻角大于等于7.5°时，共振频率960 Hz更为合适；（3） 在来流雷诺数为140 000，攻角小于等于15°时，合成射流减小了翼型上表面射流出口附近的压力值，从而使上下表面压力差增大约5%，提高了升力.

Aerodynamic Characteristics of Fixed Wing for Miniature Air Vehicle With Synthetic Jet

Synthetic jet actuator,which can be miniaturized,can improve aerodynamic performance of airfoils of miniature air vehicles(MAV)by suppressing separated flow.In this paper,synthetic jet actuator was placed into an NACA0012 airfoil to conduct wind tunnel tests.Conclusions are drawn as follows.(1)The synthetic jet significantly reduces the separation regions when the Reynolds number is 18 000 and the angle of attack is less than 15°.(2)Different frequencies of actuator are needed for various angles of attack.For example,when the angles of attack are 2.5°,5°,and above 7.5°,the proper frequencies are 1 300 Hz,400 Hz or 1 300 Hz,and 960 Hz respectively.(3)The synthetic jet can enhance the lift of airfoil by about 5% when the Reynolds number is 140 000 and the angle of attack is less than 15°.