We study drop impact on a deep pool of the same fluid, with an emphasis on the air layer trapped under the droplets from its formation to its rupture. The penetration velocity of the air layer at a very short time scale prior to its rupture is shown, using an energy argument and experimental verification, to be one-half of the impact velocity. We then deduce the dependence of the rupture positi...

[1] The effect of cloud droplet sedimentation on the entrainment rate and liquid water path of a nocturnal nondrizzling stratocumulus layer is examined using largeeddy simulations (LES) with bulk microphysics. In agreement with a prior study by Ackerman et al. (2004), sedimentation is found to decrease entrainment rate and thereby increase liquid water path. They suggested this is due to reduct...

Sudden pipe expansions have been known as efficient hydraulic energy dissipaters for a long time. The complex phenomenon of flow separation and velocity discontinuity at the interface of incoming jet and the recirculation flow, results in intensive shear and tensile rupture of the fluid and the associated destructive phenomenon of cavitation. This paper focuses on aeration in sudden pipe expans...

Efficient turbulent entrainment causes otherwise dense volcanic jets to rise high into the atmosphere as buoyant plumes. Classical models suggest that the inflow of air is 10–15% of the axial velocity, giving predictions for the height of the plume and, in turn, the composition and structure of the resulting umbrella clouds. Crucially, entrainment is assumed independent of source geometry and m...

Vascular air embolism (VAE) is known since early nineteenth century. It is the entrainment of air or gas from operative field or other communications into the venous or arterial vasculature. Exact incidence of VAE is difficult to estimate. High risk surgeries for VAE are sitting position and posterior fossa neurosurgeries, cesarean section, laparoscopic, orthopedic, surgeries invasive procedure...

In many industrial processes, such as pouring a liquid or coating a rotating cylinder, air bubbles are entrapped inside the liquid. We propose that this is due to air being drawn into the narrow channel of a cusp singularity that generically forms on free surfaces. Since the width of the cusp is exponentially small in the driving strength, even the minute viscosity of air is enough to destroy t...

Flotation process in mechanical cells is carried out in highly turbulent conditions. In this work, the impact of impeller speed on four characteristics of the quiescent zone, i.e. zone height, turbulence, solid percentage, and gas holdup, and their relationship with the entrainment is investigated, and it is shown why at a higher impeller speed, entrainment is not significant. The height of the...

Pulsed saline lavage is used to prepare bony surfaces during joint replacement surgery. A patient is described in whom a venous air embolism occurred as a result of a combination of the increased vascularity of bone seen in Paget's disease and possible air entrainment in the lavage equipment.

13 A new particle-resolved three dimensional direct numerical simulation (DNS) model is 14 developed that combines Lagrangian droplet tracking with the Eulerian field representa15 tion of turbulence near the Kolmogorov microscale. Six numerical experiments are per16 formed to investigate the processes of entrainment of clear air and subsequent mixing with 17 cloudy air and their interactions wi...