The temporal linear instability of an inviscid capillary liquid jet with a source of mass is investigated. Two different spatial mass distributions are considered. In the first case, mass is added uniformly everywhere in the jet. In the second case, mass is added uniformly in the radial direction, but allowed to change along the axial direction. The problem is solved using a one-dimensional approximation for the capillary jet. An analytical solution for the steady basic flow of a jet with a small source of mass is obtained. The dispersion relation and the growth rate of the disturbances are obtained analytically for small source terms. The influence of the mass addition on the instability characteristics, the breakup time, and the breakup length of a jet are presented. It is shown that the mass addition decreases the rate of growth of the disturbances. The mass addition increases the breakup time and decreases the breakup length. Also, the sizes of the generated drops increase with increasing the source of mass.
A numerical study is performed to examine the effect of introducing a swirling desolvation gas flow on the flow transport characteristics in an electrospray and an atmospheric pressure chemical ionization (APCI) system. An ion source having three coaxial tubes is considered: (1) an inner capillary tube to inject the liquid sample, (2) a center coaxial tube to provide a room temperature gas flow to nebulize the liquid, referred to as the nebulizing gas flow, and (3) an outer coaxial tube having a converging exit to supply a high temperature gas for droplet desolvation, referred to as the desolvation gas flow. The results show that a swirling desolvation gas flow reduces the dispersion of the nebulizing gas and suppresses turbulent diffusion. The effect of swirling desolvation flow on the trajectory of a range of droplet sizes emitted from a source is also considered.
The present study is conducted to investigate the details and characteristics of swirling submerged jets when transferred into a system of helical vortices downstream in a bathtub-like flow. Both analytical and numerical results are presented. In the analytical solution, upstream flow is considered to be two-dimensional with piecewise-constant vorticity profile. The instability of such a flow leads to the formation of two-dimensional dipolar or tripolar vortical structures. It is shown that the size of the vortexless annular area inside the initial vortex is a critical parameter in the two dipolar unstable or tripolar stable structure formations, and that such tripolar flow transforms downstream to a three-dimensional steady helical vortex system, which rotates as a whole and propagates in the downstream direction. The mechanism of screwing vortex filaments into a steady system of helical vortices is also presented. The numerical simulations also confirm the initiation and generation of dipolar vortex structures.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.