三电极等离子体合成射流激励器工作特性参数影响实验

Experimental Study of the Parameters Influence on Flow Characteristic of the Three-Electrode Plasma Synthetic Jet Actuator

采用放电测量和光学诊断技术对三电极等离子体合成射流激励器放电特性及流场特性进行了实验研究分析了放电电容、激励器腔体体积和射流出口直径对三电极等离子体合成射流流场分布及速度特性的影响.实验结果表明三电极等离子体合成射流激励器放电过程包含触发、放电增强、放电衰减和电弧熄灭4个阶段表现出典型的欠阻尼放电特征等离子体合成射流流场包含射流主流、"前驱激波"和复杂的反射波系.放电电容、腔体体积和射流出口直径均存在一阈值当电容和出口直径小于阈值、腔体体积大于阈值时"前驱激波"以当地声速(约345 m/s)恒速传播否则"前驱激波"则以大于345 m/s的速度传播且与射流速度呈现相同的变化趋势即随着放电电容和出口直径的增加而增大随着腔体体积的增加而减小.

Discharge and flow characteristics of a three-electrode plasma synthetic jet actuator have been experimentally studied by discharge measurements and high-speed shadowgraphy technology,the influence of capacitor,cavity volume and exit diameter on flowfield and speed of the actuator are analyzed.Results show that the discharge is a typical underdamped discharge and the period includes discharge trigger,discharge enhance,discharge decay and arc off.The flowfield of the plasma synthetic jet is composed by main jet,precursor shock and complicated reflect shock.Jet speed will increase with the increase of the capacitor and exit diameter and decrease with the increase of cavity volume.All of capacitor,cavity volume and exit diameter have threshold value,when the capacitor and exit diameter less than the threshold value,or cavity volume greater than the threshold value,the speed of the precursor shock is invariant and is about 345m/s.Otherwise,the variation trends of the precursor shock speed are similar with the jet.