Characterization Of A Plasma Synthetic Jet Actuator With Slot Orifice And Its Array Effect

The plasma synthetic jet is a novel active flow control technology characterized by high control capability,adjustability of parameters,low energy consumption and high reliability,etc.The outlet of the actuator in previous researches is always designed as a single normal orifice.However,the area of flow control must be extended for practical applications,which can be realized by substituting the outlet from orifice to slot and using multiple slots.Based on these,the plasma synthesis jet actuators with multiple slots are designed and ground experiments are conducted.Finally,preliminary supersonic flow control experiments using the plasma synthesis jet actuators with multiple slots are performed.First,the characteristics of four types of actuators with single outlet are experimentally studied and compared.The potential advantages of actuators with pitched slot on flow control are analyzed.Compared with normal-orifice actuators,the transient flow of actuator with pitched orifice has a strong tendency of attaching the solid surface forming distinctive wall-attaching jet.This feature is beneficial for momentum supplementation in the boundary layer.In addition,the shapes of compression wave and jet of actuator with slot appear to be ellipsoid which has a larger uniform flow region and can contribute to an enlarged the flow control area.Then,the periodic operating characteristics of actuator with multiple pitched slots are studied.The experimental results demonstrate that the actuator is able to work properly with the operating frequency of 600 Hz,1200Hz,1800 Hz,and 2400 Hz.With the increasing of the operating frequency,the breakdown voltage of the actuator decreases gradually,and the jet intensity is weakened.Finally,a plasma synthetic jet actuator with multiple large interval slots operated under low pressure condition is designed to meet the requirement of high-altitude condition.High-speed Schlieren technology and electric parameter measurement system are utilized to analyze the characteristics of the flow field and discharging for the actuator under different atmosphere pressure conditions.Besides,the interaction of jet and oblique shock wave is observed for the first time in the control experiment of supersonic compression ramp.The plasma synthetic jet actuators with multiple slots show strong control ability and can suppress the separation efficiently.