Numerical simulation of mixing control for coaxial jets with synthetic jet

A numerical simulation has been conducted to investigate the mixing of coaxial jets with zero-mass-flux synthetic jet actuators, two arrays of which are placed around coaxial jets and in the exit plane of the outer primary jet. Both the velocity field of the primary jet and mixing processes were studied. The comparison was made between the control effectiveness of two arrays of actuators and that of an array of actuators. The results show both of the synthetic jet actuator configurations can result in the significant mixing enhancement, but the former exhibits higher effectivness, which mainly results from the stronger control capability of adjacent synthetic jets. After the vortex pairs of adjacent synthetic jets couple with each other, the new stronger vortex pair forms and affects the ambient fluid as a new synthetic jet.