Simulation of Bubble Breakup Dynamics in Homogeneous Turbulence

Abstract

This article presents numerical simulation results for the deformation and breakup of bubbles in homogeneous turbulence under zero gravity conditions. The lattice Boltzmann method was used in the simulations. Homogeneous turbulence was generated by a random stirring force that acted on the fluid in a three-dimensional periodic box. The grid size was sufficiently small that the smallest scales of motion could be simulated for the underlying bubble-free flow. The minimum Weber number for bubble breakup was found to be about 3. Bubble breakup was stochastic, and the average time needed for breakup was much larger for small Weber numbers than for larger Weber numbers. For small Weber numbers, breakup was preceded by a long period of oscillatory behavior during which the largest linear dimension of the bubble gradually increased. For all Weber numbers, breakup was preceded by a sudden increase in the largest linear dimension of the bubble. When the Weber number exceeded the minimum value, the average surface area increased by as much as 80%.

Energy Optimization of Gas–Liquid Dispersion in Micronozzles Assisted by Design of Experiment

“…A critical Weber number for laminar breakup is derived from Figure 8b and determined as , ≈ 3. Data from simulations [60] and experiments [61] show similar critical Weber numbers Resulting from these experiments, the region of interest is narrowed down to 10% < ϕ < 20% and 20 mL/min < . V tot < 160 mL/min, as the aim of this study is the refinement of bubbly flow.…”

“…A critical Weber number for laminar breakup is derived from Figure 8b and determined as , ≈ 3. Data from simulations [60] and experiments [61] show similar critical Weber numbers A deformation of a bubble is observed for low volumetric flow rates only. The external forces acting on the surface boundary result in phase boundary oscillation.…”

“…A critical Weber number for laminar breakup is derived from Figure 8b and determined as We crit,lam ≈ 3. Data from simulations [60] and experiments [61] …”

Direct Numerical Simulation of Turbulent Flows Laden with Droplets or Bubbles

“…A validation test was made for a non-turbulent flow by comparing the results of this LBM with those of FTM for a 2D rising bubble and good agreement was achieved (Sankaranarayanan et al (2003)). Qian et al (2006) defined Weber number as W e = ρ l δu 2 de/σ, where δu is the velocity difference over a distance equal to the bubble equivalent spherical diameter, de, and .. denote averaging over space and time. The results show that prior to bubble breakup, an increase in the bubble surface area by at least 37% occurs.…”

Determining the droplet size in the spray extractor

“…Ввод диспергированной фазы в колонну осуществляется методом распыления диспергированной фазы с помощью распылительного устройства. В зависимости от объемной подачи диспергируемого компонента наблюдается пять различных режимов работы распылительной колонны [1,[8][9][10][11][12]. Первый -редкие капли со спутниками меньших размеров.…”