The proper interpretation of bubble rising in a liquid column is critical in the investigation of the waterevapour two phase flow and heat transfer. In this paper, the bubble behaviours are studied using the combination of Level Set Method (LSM) and moving mesh method in a collocated grid. Level set method is used to track the interface of the bubble, which has many advantages over other interf...

We report exploratory experiments simulating gas-driven eruptions using the C02H20 system at room temperature as an analog of natural eruptive systems. The experimental apparatus consists of a test cell and a large tank. Initially, up to 1.0 wt % of C02 is dissolved in liquid water under a pressure of up to 735 kPa in the test cell. The experiment is initiated by suddenly reducing the pressure ...

Abstract Bubble column is a commonly used multiphase reactor. Owing to the complicated nature of its flow structure, computational fluid dynamics has frequently been as useful instrument for studying mechanics in bubble column. However, most previously studied systems are air-water system, while air-nitric acid solution system rarely reported. In present study, differences size distribution pur...

The classical penetration theory was corrected and then applied for the semi-theoretical prediction of mass transfer coefficients kLa in a slurry bubble column operated in the homogeneous regime. The gas-liquid contact time was expressed as a ratio of bubble surface to the rate of surface formation. These terms were defined for the case of oblate ellipsoidal bubbles formed under homogeneous flo...

A free-Lagrange numerical method is implemented to simulate the axisymmetric jetting collapse of air bubbles in water. This is performed for both lithotripter shock-induced collapses of initially stable bubbles, and for free-running cases where the bubble initially contains an overpressure. The code is validated using two test problems (shock-induced bubble collapse using a step shock, and shoc...

-The effect of elevated pressure on the stability of the homogeneous bubbly flow regime in a gas-liquid bubble column is examined. Experiments were performed in a 0.15 m diameter bubble column operated at pressures in the range 0.1-1.3 MPa with nitrogen as the gas phase and water as the liquid phase. The transition from homogeneous to heterogeneous flow regime was determined by two procedures. ...

The flotation circuit in Sungun copper plant consists of two column flotation cells as cleaner, having fixed-spargers system. To achieve the expected aims in flotation step, there are serious operational challenges such as: fast choking of the static mixers, boiling problem, burping phenomena and pulp overflow to concentrate lander, maintenance and control problems. An attempt was exerted by im...

In this paper attempts are made to address how bubble behaviour in a batch oscillatory ba'ed column (OBC) contributes to the overall measured enhancement in mass transfer. A CCD camera is used to measure the bubble size distribution and the gas hold-up in the OBC. The experimental results of Sauter mean diameter and gas hold-up are correlated as a function of the power dissipation and super5cia...

We report a parallel algorithm applicable to a Euler–Lagrange model embedding four-way coupling. The model describing the dispersed phase dynamics accounts for bubble–bubble collisions and is parallelized using a mirror domain technique while the pressure Poisson equation for the continuous phase is solved using a domain decomposition technique implemented in the PETSc library [S. Balay, K. Bus...

Bursting of bubbles at an air/liquid interface is a familiar occurrence relevant to foam stability, cell cultures in bioreactors and ocean–atmosphere mass transfer. In the latter case, bubble-bursting leads to the dispersal of sea-water aerosols in the surrounding air. Here we show that bubbles bursting at a compound air/oil/water-with-surfactant interface can disperse submicrometre oil droplet...