CFD Simulation of Gas-Liquid Two-Phase Flow Through an Orifice in Millimeter-Scale Rectangular Channel

A numerical model is developed and used to simulate gas-liquid two-phase flow through a plate orifice in a millimeter-scale channel. The channel width is 50 mm and the height is varied from 1.00 mm to 2.00 mm. The contraction ratio and thickness of the orifice are varied over the range 0.04–0.4 and 5–20 mm respectively. The model utilized is based on the multiphase-mixture principle in which transport equations are solved for the mixed phase velocities with allowance for interpenetration of phases and intra-phase transfer processes. The predicted velocity profiles are successfully validated by comparison with the available experimental data for the mixture velocity. The predictions also extend beyond the experimental data to provide the detailed effect of contraction ratio on the flow and gas fraction distribution in the channel. In the range of parameters investigated, the predictions indicate that the flow in such channels will produce no wake in the lee of the orifice for contraction ratios >0.2.