Jets, ie collimated streams of matter, occur from the microscale up to the large-scale structure of the universe Our focus will be mostly on surface tension effects, which result from the cohesive properties of liquids Paradoxically, cohesive forces promote the breakup of jets, widely encountered in nature, technology and basic science, for example in nuclear fission, DNA sampling, medical diagnostics, sprays, agricultural irrigation and jet engine technology Liquid jets thus serve as a paradigm for free-surface motion, hydrodynamic instability and singularity formation leading to drop breakup In addition to their practical usefulness, jets are an ideal probe for liquid properties, such as surface tension, viscosity or non-Newtonian rheology They also arise from the last but one topology change of liquid masses bursting into sprays Jet dynamics are sensitive to the turbulent or thermal excitation of the fluid, as well as to the surrounding gas or fluid medium The aim of this review is to provide a unified description of the fundamental and the technological aspects of these subjects

Physics of liquid jets

Chemical and physical aspects of natural organic matter (NOM) fouling of nanofiltration membranes

https://iopscience.iop.org/article/10.1016/0169-5983(93)90106-K/pdf

Phenomena of liquid drop impact on solid and liquid surfaces

Droplet-wall collisions: Experimental studies of the deformation and breakup process

The impact of drops impinging one by one on a solid surface is studied experimentally and theoretically. The impact process is observed by means of a charge-coupled-device camera, its pictures processed by computer. Low-velocity impact results in spreading and in propagation of capillary waves, whereas at higher velocities splashing (i.e. the emergence of a cloud of small secondary droplets, absent in the former case) sets in. Capillary waves are studied in some detail in separate experiments. The dynamics of the extension of liquid lamellae produced by an impact in the case of splashing is recorded. The secondary-droplet size distributions and the total volume of these droplets are measured, and the splashing threshold is found as a function of the impact parameters.The pattern of the capillary waves is predicted to be self-similar. The calculated wave profile agrees well with the experimental data. It is shown theoretically that the splashing threshold corresponds to the onset of a velocity discontinuity propagating over the liquid layer on the wall. This discontinuity shows several aspects of a shock. In an incompressible liquid such a discontinuity can only exist in the presence of a sink at its front. The latter results in the emergence of a circular crown-like sheet virtually normal to the wall and propagating with the discontinuity. It is predicted theoretically and recorded in the experiment. The crown is unstable owing to the formation of cusps at the free rim at its top edge, which results in the splashing effect. The onset velocity of splashing and the rate of propagation of the kinematic discontinuity are calculated and the theoretical results agree fairly well with the experimental data. The structure of the discontinuity is shown to match the outer solution.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022112095002266

Impact of drops on solid surfaces : self-similar capillary waves, and splashing as a new type of kinematic discontinuity

Characterization of Porous Media by the Kinetics of Liquid Penetration: The Vertical Capillaries Model☆

Colloidal fouling of reverse osmosis membranes

Based on energy and entropy principles, a statistical model describing the shattered state of a single spherical liquid drop after being subjected to a relatively sudden but uniform (over the whole surface area of the drop) impact is developed. The problem is addressed from a fundamental standpoint, with the intention of providing a predictive framework for the various modes of breakup and the size and number of droplets produced. Upon neglecting viscous effects, several results in terms of the energy of impact, non-dimensionalized with respect to the surface energy of the drop before impact, are derived. The model is quite simple and straightforward, yet it appears to predict in a fairly consistent manner certain experimental observations that have been made repeatedly in relation to drop breakup in stirred dispersions, by collision, and exposure to shocks.

Shattering of a Liquid Drop due to Impact

Effect of viscosity on drop breakup

/pdf/the-optimal-capital-structure-of-depository-institutions-4mglcsmmay.pdf

Ruben D. Cohen

Papers

Characterization of Porous Media by the Kinetics of Liquid Penetration: The Vertical Capillaries Model☆

Colloidal fouling of reverse osmosis membranes

Shattering of a Liquid Drop due to Impact

Effect of viscosity on drop breakup

The optimal capital structure of depository institutions