Numerical Simulation of Gas-liquid Slug Flow in a Wet Microtube

In this paper، direct numerical simulation of two-phase incompressible gas-liquid flow for simulation of bubble motion in a microtube is presented. Microtube radius is 10 μm. The interface is tracked using volume of fluid (VOF) methodwith continuous surface force (CSF) model. The flow is solved using a finite volume scheme، based on PISO algorithm. Numerical simulation is performed on a axisymmetric mesh with cyclic boundary condition for different values of pressure gradient، void fraction، and bubble period. The mean pressure gradient is fixed for each simulation and the superficial Reynolds numbers of gas and liquid are 0. 3 – 7 and 5 – 210، respectively. The numerical results are coincident with Serizawa regime map and there is a linear relation between void fraction and gas flow ratio. Pressure drop and liquid film thickness are compared with different empirical correlations. The computed liquid film thickness is closer to Irandoust correlation.