A two-dimensional air-fluidized bed of 600 mm width and 1000 mm height was studied to investigate the formation, rise and cracking process of a bubble. The particles were assumed to be regular round particles of diameter 4 mm. The RNG k-ε model was employed for the turbulence, and the time integration scheme is the first order implicit difference with the time-step 0.0001 s. The equations were ...

-In storm waterways and at dam outlets, high-velocity supercritical flows are characterized by substantial air bubble entrainment. The entrainment of fine air bubbles and the strong turbulent mixing contribute both to the air-water transfer of volatile gases (e.g. oxygen, nitrogen, VOC). The paper describes new experimental data obtained in a 25 m long channel with a 4 ° slope. The analysis of ...

This paper presents an enhancement to the free surface lattice Boltzmann method (FSLBM) for the simulation of bubbly flows including rupture and breakup of bubbles. The FSLBM uses a volume of fluid approach to reduce the problem of a liquid-gas two-phase flow to a single-phase free surface simulation. In bubbly flows compression effects leading to an increase or decrease of pressure in the susp...

We implement a semi-analytic scheme for numerically computing high order polynomial approximations of the stable and unstable manifolds associated with the fixed points of the normal form for the family of quadratic volume-preserving diffeomorphisms with quadratic inverse. We use this numerical scheme to study some hyperbolic dynamics associated with an invariant structure called a vortex-bubbl...

Condensation of a spherically symmetric submicrometer size vapor bubble is studied using diffuse interface hydrodynamic model supplemented by the van der Waals equation of state with parameters characteristic for argon. The bubble, surrounded by liquid, is held in a container of constant volume with temperature of the wall kept fixed. The condensation is triggered by a sudden rise of the wall t...

The effect of distributed bubble nuclei sizes on shock propagation in a bubbly liquid is numerically investigated. An ensemble-averaged technique is employed to derive the statistically averaged conservation laws for polydisperse bubbly flows. A finite-volume method is developed to solve the continuum bubbly flow equations coupled to a single-bubble-dynamic equation that incorporates the effect...

Bubble damping in displacement-driven microfluidic flows was theoretically and experimentally investigated for a Y-channel microfluidic network. The system was found to exhibit linear behavior for typical microfluidic flow conditions. The bubbles induced a low-pass filter behavior with a characteristic cutoff frequency that scaled proportionally with flow rate and inversely with bubble volume a...

The classical isoperimetric problem seeks the least-area way to enclose a single region of prescribed volume. About 200 BC, Zenodorus argued that a circle is the least-perimeter enclosure of prescribed area in the plane (see [Heath 60]). In 1884, Schwarz [Schwarz 1884] proved by symmetrization that a sphere minimizes surface area for a given volume in R. Isoperimetric problems arise naturally i...