Vectoring mechanisms and vortex dynamics of impinging adjacent synthetic jets

Synthetic jets have emerged over the past two decades as a viable application, particularly for electronic cooling and boundary layer control, in configurations involving single, dual, and multiple jets. When two Adjacent Synthetic Jets (ASJs) operate under the right conditions, they can merge into a larger jet that tilts relative to the streamwise direction, a phenomenon known as vectoring. In this study, we investigate synthetic jets from the perspective of vortex dynamics to understand the physical mechanisms that drive the vectoring process. We conducted numerical simulations using the Finite Volume Method and the k-ω SST turbulence model with ANSYS Fluent™. Our research focused on four key governing parameters: the vortex Reynolds number (Re_Γ), the distance between the jets (S), the jet-to-wall distance (H), and the phase difference between the jets (ΔΦ). We introduced a novel approach to assess the Vectoring Angle by tracking the stagnation point on the impinging wall, defined as the location of zero vorticity. Within the parameters of our study, the Vectoring Angle reached a maximum of approximately 20°. Our analysis revealed that stronger vectoring occurs due to a persistent vortex that induces spanwise advection. In contrast, poor vectoring is associated with a large trapped vortex, which typically appears at larger S values.