Numerical 3D simulation of developing turbulent stratified gas-liquid flow in curved pipes consisting of entrained particles through this type of flow

Predicting multiphase flows in curved pipes is of great importance in industrial equipment. In the present study, a computational model for predicting the velocity profile is developed and used to study the developing turbulent gas-liquid- solid three dimension flow in curved pipes. In order to discretize and solve the three-dimensional steady-state momentum equations, the finite volume scheme on staggered grids besides central difference and QUICK scheme have been used. Moreover, the k-ε model is employed to reflect the nature of turbulence in the flow. In order to address the needs for sooner convergence and convenient mapping of the physical domain, the computations have been performed in an extended toroidal coordinate system. Particle tracking has been done using Lagrangian approach in which two-way coupling regime is considered. In terms of validation, the numerical simulation results for the straight duct (infinite curvature), have been compared with the analytical solution and previous experimental results. Moreover, injection of particles through the flow indicates that, in each section of the bend, trade-off between centrifugal and pressure gradient forces plays a key role on particles motion. In last section, the effects of particle diameter and bend curvature on particle motion have been examined.