Numerical Simulation of the Two-Phase Flow at a Single Trapezoid Fixed Valve Using a Hybrid CFD Approach

In the present contribution, we demonstrate the application of a hybrid CFD approach, which allows for simulating dispersed phases as well as resolved interfaces within an Eulerian framework, for the flow on distillation trays for the first time. The morphology adaptive multi-field two-fluid model is exemplified for a generic tray setup with a single trapezoid fixed valve. Instead of fully resolving its geometry in the computational grid, we emulate the gas inlets by implementing local mass and momentum sources. Different source term implementations are tested and compared: continuous gas vs. dispersed gas sources and steady vs. dynamic sources. The simulation results are verified with experimental data from a lab-scale test rig with air-water flow. Local phase fractions were measured using a conductivity sensor array. The comparison of simulated and experimental results reveals that the relevant time-averaged and transient flow characteristics can be predicted satisfactorily when choosing proper source term implementations.