The momentum-transfer performance of a plasma actuator over a 20° conical fore-body is studied experimentally for the effects of periodic pulse in the absence of external flow. A two-dimensional particle image velocimetry (PIV) is used to measure crossflow velocity field a-round the body in atmospheric air. The time-averaged spatial and temporal distributions of induced maximum cross-flow velocity and maximum magnitude of axial-vorticity at various phase angles in the neighborhood of the body are investigated. Experimental results indicate that the main mechanism of momentum transfer under periodic pulsed actuation is the formation of strong discrete vortices, rather than the gas acceleration and the input power can be saved by using periodic pulsed actuation that is able to utilize the flow hysteresis.%静止大气下,对施加脉冲周期介质阻挡放电,半顶角为10°的圆锥前体进行了PIV实验研究.采用总平均和相位锁定平均方法对脉冲周期放电进行了分析；对比了不同占空比和不同相位角沿θ=90°半径上的切向速度和轴向涡量分布,得到了在圆锥表面等离子体诱导的最大速度和最大涡量；分析了脉冲周期放电的动量转移特性.实验结果表明:脉冲周期放电引发动量转移的主要机制是涡的增强而非气流的加速；当激励器处于脉冲放电间歇时,相位锁定平均的最大速度和最大涡量不为零,存在流动滞后效应,有利于节省能耗.
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