Fluid convection and mixing induced by bubble-propelled tubular microengines are characterized using passive microsphere tracers. Enhanced transport of the passive tracers by bubble-propelled micromotors, indicated by their mean squared displacement (MSD), is dramatically larger than that observed in the presence of catalytic nanowires and Janus particle motors. Bubble generation is shown to pl...

We report an experimental study of bubble dynamics in a non-Newtonian fluid subjected to a pressure decrease. The fluid is a hydrogel, composed of water and a synthetic clay, prepared and sandwiched between two glass plates in a Hele-Shaw geometry. The rheological properties of the material can be tuned by the clay concentration. As the imposed pressure decreases, the gas initially dissolved in...

A bubble coalescence model is developed using an Euler–Lagrangian approach for unstructured grids. The Eulerian carrier fluid is solved using large-eddy simulation (LES) and the Lagrangian particle motion is solved with equations relating the turbulent motion of the carrier fluid to forces on each discrete bubble. The collision process is deterministic; bubble–bubble collisions are assumed to b...

carbon dioxide flooding is considered to be one of the most effective enhanced oil recovery methods for the light oil reservoirs. depending on the operating pressure, the process might be miscible or immiscible. minimum miscibility pressure (mmp) is the most important parameter for assessing the applicability of any miscible gas flood for an oil reservoir. the miscibility condition is determine...

The rise and deformation of a gas bubble in an otherwise stationary liquid contained in a closed, right vertical cylinder is investigated using a modified volume-of-fluid (VOF) method incorporating surface tension stresses. Starting from a perfectly spherical bubble which is initially at rest, the upward motion of the bubble in a gravitational field is studied by tracking the liquid–gas interfa...

Surface cleaning using cavitation bubble dynamics is investigated numerically through modeling of bubble dynamics, dirt particle motion, and fluid material interaction. Three fluid dynamics models; a potential flow model, a viscous model, and a compressible model, are used to describe the flow field generated by the bubble all showing the strong effects bubble explosive growth and collapse have...

This paper presents a 3D numerical study of the bubble generation process in a T-junction, performed with the commercial Computational Fluid Dynamics solver ANSYS Fluent v15.0.7. Numerical results on bubble generation frequency, bubble velocity, volume void fraction, bubble volume, and characteristics bubble lengths are compared with experimental data. Additionally, a new simple tting for the b...

Bubbles in coating color greatly influence the paper quality and coater runnability. It is particularly important technology to remove bubbles for the paper coating industry. Recently, one of the authors has developed a novel device using swirl flow capable of eliminating bubbles and decreasing dissolved gases from fluid. This device is called the “Bubble Eliminator”. Using the bubble eliminato...

Numerical simulation of bubble growth during pool boiling under the influence of low frequency vibration was performed to understand the influence of common vibrations such as those induced by wind, highway transportation, and nearby mechanical devices on the performance of thermal systems that rely on boiling. The simulations were done for saturated R123 boiling at 277.6 K with a 15 K wall sup...