CFD APPROACH TO SIMULATE TWO PHASE FLOW INLINE-SEPARATOR COUPLING IBM, LES, LAGRANGIAN TRACKING AND VOF METHODS

Abstract

x Inline fluid separation using a swirl element is a recent technology for oil/gas processing. Centrifugal forces up to 100 times the gravitational acceleration separate the phases, leaving the heavy phase close to the wall and the light one in the center. The current study is part of a Europeen project TOMOCON aiming at developing CFD methods in the in-house code JADIM to simulate the two-phase flow separation in order to help the development of inline separation control. The objective is to propose a hybrid approach based on Navier Stokes solver that makes possible accurate simulations with coarse spatial resolution. First, Immersed Boundary Method (IBM) is used to simulate both the pipe and the complex geometry of the swirl element on a cartesian regular mesh. Turbulence is modeled by the classical dynamic Smagorinsky sub-grid model in Large Eddy Simulation (LES) with a special stochastic wall law coupled to the IBM allowing to avoid the need for a mesh refinement in the near wall region. A Lagrangian tracking (LT) method is used to solve the dispersed bubbly flow and it is coupled to the Volume of Fluid (VoF) approach once the coalescence takes place and the gas core is formed. The numerical strategy based on the coupling of these different methods is presented and we report some of the simulations used for the verification-validation of the numerical developments.