Pyragas Flow Control using Synthetic Jets

研究了一种带有射流喷嘴的合成射流主动流动控制系统。该控制系统由粒子跟踪测速仪、神经网络计算和吡拉加斯延迟反馈控制理论组成。合成射流设置在一次流的两侧，并与射流喷嘴相连。通过综合吸气和吹气动作，执行器可以很容易地引导一次流向上或向下流动。该系统适用于右侧壁有入口、底部有出水口的矩形水池内的自由面水流。发现该槽内有两种稳定的流型。在一种情况下，入口气流直接流向出口，观察到顺时针循环流动。在另一种情况下，进口气流附着在自由面上，产生逆时针循环流动。任何其他流型都是不稳定的，并且稳定为两种稳定的流型中的一种。虽然目标流型自然是不稳定的，但目标流型由本系统稳定。

An active flow control system using Synthetic Jets with fluidic nozzle was investigated. The control system is composed of Particle Tracking Velocimetry, Neural Network computing and Pyragas' Delayed Feedback control theory. Synthetic Jets are set on both side of primary flow, and connected to fluidic nozzle. The actuators can easily vector a Primary flow upward or downward by synthesizing suction and blowing actions. This system is applied to water flow with free surface in a rectangular tank having an inlet on the right side wall and outlet at the bottom. Two flow patterns are found to be stable in this tank. Under one condition, inlet flow goes directly to outlet and clockwise circulating flow is observed. Under the other one, while, inlet flow is attached to free surface, resulting in counterclockwise circulating flow. Any other flow pattern is unstable and stabilized to either two stable ones. A target flow pattern is stabilized by the present system although it is naturally unstable.