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

TL;DR: In this paper, the authors studied the evolution of the fingering pattern at the edge of a thin jet during the impact of a water drop on a glass plate and showed that systematic changes in frontal shapes take place during the expansion.

Abstract: In this chapter drop impacts onto a liquid layer of the same liquid as in the drop are considered. The chapter begins with consideration of such weak drop impacts on a liquid layer that they result only in capillary waves propagating over the surface. An interesting feature of these waves is that they are self-similar (Section 6.1). In the following Section 6.2 crown formation in strong (high-velocity) impacts onto thin liquid films is considered. Normal and oblique impacts of a single drop onto a wet wall are studied, as well as crown–crown interaction in sprays impacting the wall. Also, the evolution of the free rim on top of the crown is described. Then, in Section 6.3 drop impacts onto a thick liquid layer are considered and the dynamics of the crater formation is explained. Drop impacts onto a wet wall leave a residual liquid film on the wall which is addressed in Section 6.4. Drop impacts onto deep liquid pools produce a plethora of interesting morphological structures considered in Section 6.5. In the following Section 6.6 bending instability of a free rim is considered and the splashing mechanism is discussed. Splashing resulting from impacts of drop trains one-by-one is discussed in Section 6.7, where its physical mechanism and the link to splashing of a single drop impacting onto a liquid layer are elucidated. Several other regimes of drop impact are also mentioned. Drop Impact onto Thin Liquid Layer on a Wall: Weak Impacts and Self-similar Capillary Waves Consider patterns of capillary waves propagating over the free surface of a thin liquid film from the point where it was impacted normally by a tiny droplet or a stick (Fig. 6.1), as an example of a relatively weak (low-velocity) impact. For scales of the order of several millimeters the gravity effect on these waves is negligibly small, and for time scales of the order of several milliseconds viscosity effects can also be neglected.

TL;DR: In this paper, an approche par prediction avec un modele semi-empirique a ete adoptee is presented, associe des resultats experimentaux a une simulation numerique.

TL;DR: The physical and chemical condition of emulsions of two fluids which do not mix has been the subject of many studies, but very little seems to be known about the mechanics of the stirring processes which are used in making them.

TL;DR: In this paper, various topics in the area of combustion and explosives are discussed, including basic physical concepts of the science of combustion, the time-independent theory of thermal explosions, time-dependent statement of the problem of the initiation of chemical reaction waves in fuel mixtures, laminar flames, complex and chain reactions in flames, the gas dynamics of combustion dynamics, and diffusional combustion of gases.

TL;DR: In this paper, the authors present the theory of the boundary layer of a two-dimensional Turbulent Jet of Incompressible Fluid and its application to heat and diffusion problems, and determine the temperature profile in a Jet on the basis of the New Prandtl-Gortler Theory of Turbulence.