Influence of Orifice Geometry on the Flow Characteristics of Elliptical Dual Synthetic Jets

Dual synthetic jets (DSJs) are an active flow control technique that combines high energy efficiency with structural simplicity. In this study, numerical simulations were conducted to systematically investigate the effects of elliptical orifice aspect ratio (AR) on the velocity distribution, diffusion characteristics, and vortex dynamics of DSJs. The results show that increasing AR enhances jet spreading in the x, y-plane while suppressing spreading in the y, z-plane. Flow visualization reveals that, in addition to the primary vortex ring (PVR), several periodic and organized secondary vortical structures are generated, including streamwise vortices (SV-0, SV-1, and SV-2) and arc vortices (AVs). Among these, SV-0 and SV-2 are unique to DSJs, whereas SV-1 and AVs also appear in high-AR single synthetic jets. This indicates that although DSJs share certain topological similarities with single synthetic jets, they exhibit more complex vortical structures with multiscale evolutionary characteristics. Moreover, as the AR increases, both the diversity and complexity of additional vortical structures in DSJs increase significantly. Overall, this study deepens the understanding of AR-dependent vortex dynamics in elliptical DSJs and provides theoretical guidance for the geometric design and optimization of synthetic jet actuators in aerospace flow control applications.