Axis-switching and breakup of low-speed elliptic liquid jets

Shifting and breakup instabilities of squeezed elliptic jets

“…A shift of the fastest growing wavenumber to larger wavenumbers (or smaller wavelengths) implies that smaller drops will be obtained for an elliptic jet as compared to a circular jet of the same volume. These trends are in agreement with the experiments (Amini and Dolatabadi, 2012) and predictions of 1D Cosserat theory .…”

“…Therefore, the growth rates become higher and the range of unstable wavenumbers is found to increase. A similar trend for growth rates with ellipticity was observed in the experiments (Amini and Dolatabadi, 2012) and predictions of 1D Cosserat theory .…”

“…As a liquid jet flows downstream from an elliptic orifice, it is found to exhibit a flow wherein the major and minor axes switch periodically (Amini and Dolatabadi, 2012). Bechtel had studied this phenomenon theoretically, illustrating the effects of surface tension, viscosity, inertia and gravity on axis-switching (Bechtel, 1989).…”

“…It is important to note here that it is the uniform ambient pressure that results in the elliptic jet exhibiting axis-switching. It has been reported that elliptic jets are more unstable as compared to circular jets Amini and Dolatabadi, 2011;Kasyap et al, 2009;Amini and Dolatabadi, 2012) and axis-switching is attributed to be the cause of its increased destabilization (Kasyap et al, 2009). Thus, for a jet exiting an elliptic orifice, factors affecting its stability are twofold: (a) elliptic cylindrical geometry of the interface resulting in capillary instability solely due to its curvature (b) departure of elliptic cross-section from the equilibrium circular configuration (a circular cross-section is the equilibrium configuration of the interface in a uniform pressure ambient fluid) resulting in axis-switching.…”

A Comprehensive Review on Fluid Dynamics and Transport of Suspension/Liquid Droplets and Particles in High-Velocity Oxygen-Fuel (HVOF) Thermal Spray

“…It is proved that the dynamic surface tension is more appropriate than the static surface tension to study the spray characteristics of surfactant solutions and suspensions [136]. Measurements of oscillating free jets, where a fluid comes out of an elliptical nozzle, together with an analytical model have long been used to determine the dynamic surface tension [137][138][139][140][141][142][143][144][145]. Noticeably, the value of the surface tension of pure fluid can only be applied for a dilute suspension with a low concentration of surfactant.…”