Active Control of Sprays Using a Single Synthetic Jet Actuator

The effect of a single synthetic jet on an air atomized solid cone spray was investigated experimentally for several spray flow rate ratios and synthetic jet momentum coefficients. Particle image velocimetry (PIV) was used to assess the effect of the synthetic jet actuation on global spray behavior, while shadowgraphy and particle tracking velocimetry (PTV) were used at 45 locations throughout the 3D spray flow field to measure its microscopic characteristics in order to understand the influence of the synthetic jet on droplet size, distribution, and concentration. The synthetic jet was able to vector the spray up to about 18° away from the jet with increased vectoring, spray width, and RMS. Shadowgraphy measurements indicate that for low flow rate ratios, small droplets are pushed across the spray, resulting in increased concentration of small droplets on the side away from the synthetic jet. For high flow rate ratios, the number of large droplets is increased along the centerline of the spray, indicating coalescence of small droplets, as they are vectored by the synthetic jet.