Gas-liquid Flow In Bubble Column Research Articles

Computation of gas-liquid flow in a square bubble column with Wray-Agarwal one-equation turbulence model

The newly proposed one-equation Wray-Agarwal (WA) turbulence model coupled with Euler-Euler (E-E) approach was used to simulate the gas-liquid flow in a square bubble column, which further validated the accuracy and expanded the application of the WA model comparing to a preliminary study (Ouyang et al., 2019). All simulation results of the WA model were compared with two widely used turbulence models of standard k-ε and SST k-ω and literature data. The numerical results of the time-averaged axial liquid and gas velocity were validated with experimental data, and it was found that the WA model showed overall the best agreement. Profiles of turbulent kinetic energy, turbulent dissipation rate, turbulent viscosity and gas holdup were investigated at three different heights. Results for the first time validate the WA model based on the turbulent characteristic values of gas-liquid flow in the bubble column, which shows its promising prospective in multiphase flow simulation.

CHARACTERIZATION OF GAS-LIQUID FLOWS IN RECTANGULAR BUBBLE COLUMNS USING CONDUCTIVITY PROBES

ABSTRACT Unsteady gas-liquid flows in bubble columns are comprised of various flow processes occurring with varying length and time scales and govern mixing and transport processes. In the present work, we have characterized dynamic and time-averaged properties of gas-liquid flows in rectangular bubble columns using conductivity probes. The development of a single-tip conductivity probe, data processing methodology, and photographic validation procedure is discussed in detail. The effect of superficial gas velocity and aerated liquid height-to-width (H/W) ratio on voidage fluctuations and time-averaged gas holdup was investigated. The experimental data presented here can help in understanding the dynamics of various flow processes and validating computational fluid dynamics based models.

CFD simulation of steady state heat transfer in bubble columns

A low Reynolds number k-e computational fluid dynamics (CFD) model has been used for the description of flow pattern near the wall. An excellent agreement has been shown between the predicted and experimental hold-up and velocity profiles. The CFD model has been extended for the prediction of heat transfer for two-phase gas-liquid flows in bubble columns. A comparison has been presented between the predicted and the experimental data.