Pulsating jet is visualized using hydrogen bubble method to clarify the vortex nature in the near field of the jet. This study focused on the development in space and time of vortex structures evolution in low aspect-ratio rectangular jet with pulsation. Pulsation means large-amplitude, low-frequency excitation which is expected to increase the mixing and spreading of the jet and to accelerate ...

Astable regimes are common in nonlinear systems ranging from electrooptic devices to cardiac rhythms under environmental stress. Electrosprays exhibit three main axial regimes (dripping, pulsating, and cone-jet). It is generally accepted that the transition between the pulsating and cone-jet regimes is sudden, accompanied by an abruptly enhanced spray current. Here we present an alternative to ...

This work discloses similarity properties of a high aspect ratio pulsating jet with lateral confinement exhibiting axis switching in a region close to the jet exit. The analysis is conducted separately within the major and minor planes of the jet source. The similarity relations derived from the in-plane flow equations are combined with experimental data collected in a recent threedimensional v...

A variety of different types of actuators have been previously investigated as flow control devices. Potential applications include the control of boundary layer separation in external flows, as well as jet engine inlet and diffuser flow control. The operating principles for such devices are typically based on either mechanical deflection of control surfaces (which include MEMS flap devices), m...

A current-voltage characteristic of direct current (DC) gas discharge operated in a micro gas jet injected into a secondary electron microscope (SEM) chamber is presented. Ar gas was injected through a 30 μm orifice gas nozzle (OGN) and was evacuated by an additional pump to keep the high vacuum environment. Gas discharges were ignited between the OGN as anode and a counter electrode of Si wafe...

Pulsating cone-jets occur in a variety of electrostatic spraying and printing systems. This paper reports an experimental study of the pulsation frequency to reconcile two models based on a choked jet and an oscillating cone, respectively. The two regimes are demarcated by the ratio of the supplied flow rate (Qs) to the minimum flow rate (Qm) required for a steady Taylor cone-jet. When Qs . Qm,...

Recent studies of impinging jet flows have shown that momentum and heat transfer can be significantly improved if the jet flow is pulsed (Zumbrunnen, 1996). Moreover, when the jet holes are elliptical, jet free surfaces are formed into a helical structure. These helical structures in a jet flow can be readily observed by squeezing a garden hose into an elliptic shape. Upon pulsating the jet flo...