Abstract: Detailed unsteady numerical simulation has been carried to investigate the mixing of coaxial jets with zero-mass-flux synthetic jet actuator array placed side by side around coaxial jets.Firstly,the influence of an array of actuators and two arrays of actuators on the flowfield was studied,respectively,by analyzing their control effectiveness comparatively.Secondly,both the temperature fields of the primary jet and mixing processes were analyzed to study the mixing control mechanism of synthetic jet actuator array.In addition,the effect of adjacent synthetic jets was considered during the analysis.The results show that the mixing enhancement can be achieved by using synthetic jet actuators,which result from the stronger instability of flow.Both of the actuator's configurations can result in the significant mixing enhancement,but the former exhibits more stronger controlling ability due to bigger acting force of adjacent synthetic jet than that of single synthetic jet.