Numerical and Experimental Analysis of Vertical Ascendant Liquid-Gas Flow Under Action of Centrifugal and Gravitational Fields

Abstract

Two-phase flows are commonly found in the extraction and production of petroleum and the separation process involving the liquid gaseous phases has great importance. The separators used for this purpose have usually high separation efficiency, however their large dimensions make difficult the construction, installation and maintenance of these equipment in offshore applications. An alternative to reduce the dimensions of these systems is to use a distribution method that can divide the flow, making it possible to use more than one separator. This distributor ideally will produce flow rates equitably distributed across all outlets. The distribution system proposed in this work has a cyclonic chamber, where a vertical ascendant liquid film flow occurs under the action of centrifugal and gravitational fields. This study aims to analyze the development and behavior of the liquid film flow and the efficiency of the distribution system as a function of the liquid and gas flow rates, using an experimental setup and CFD simulations performed with the software ANSYS-CFX 15.0. For the experimental setup a Wire-mesh sensor with 12×12 wires and two others with 8×8 wires were used in order to analyze the variation of the thickness of the liquid film formed in the cyclonic chamber and evaluate the flow pattern at the inlet of the system. In the numerical study, a three-dimensional hybrid mesh was constructed, using the Eulerian-Eulerian two fluid model coupled with the compressive discretization scheme to capture the liquid-gas interface, the Shear Stress Transport (SST) turbulence model and the finite volume based on finite elements. It was possible to carry out a numerical model validation through a comparison with the experimental data. The development of this numerical model might help the advance of new technologies applied in the petroleum industry and this study is focused on area that lacks more studies related to vertical ascendant liquid film flows under centrifugal and gravitational field effects.