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TransAT Tutorial Manual       7.2. Two-phase slug flow in TransAT–OLGA coupled simulation


               7.2     Two-phase slug flow in TransAT–OLGA coupled simulation


               Please note: this tutorial makes use of Advanced Initial Conditions. Microsoft SDK is required
               to run it.


               7.2.1    Prerequisites

                   • TransAT

                   • TransATUI

                   • Advanced Initial Conditions
                   • Paraview (or Tecplot)

                   • OLGA (supported version is 7.2)


               7.2.2    Introduction

               Gas–liquid flow appears in various industrial processes, particularly in the petroleum industry,
               where mixtures of gas with associated liquids (light and heavy components of oil, solid particles,
               hydrates, condensate and/or water) are produced and transported together. Slug flow is a com-
               monly observed pattern in horizontal and upslope gas liquid flows. The regime is associated with
               large coherent disturbances, owing to an intermittent appearance of aerated liquid masses that
               fill the pipe cross-section and travel downstream.


               In this tutorial, a stratified flow in a pipe is studied. Air and water fills the domain and the
               transition from stratified to slug flow regime associated with the sudden growth of interfacial
               waves owing to the Kelvin–Helmholtz instability has been studied. In (Lakehal et al., 2012) we
               have studied this problem using a 2D simulation of a 8m long horizontal pipe. It has been shown
               that a slug frequency position occurs approximately 5m downstream.


               In this tutorial we will test the capability of the TransAT–OLGA coupling model. 2m of the
               upstream pipe is simulated with a 2D TransAT domain connected to an OLGA domain simulating
               100m pipe downstream.
                   The problem setup is given as follows:

                   • The 2D domain is 2.214m × 0.12m in the x − z plane, resolved with a mesh 124 × 22 ×
                     1. Inside the domain, an horizontal pipe is simulated, whose diameter is 8cm. Two inflows
                     are defined close to the upstream part of the pipe: air is flowing inside the domain from the
                     top, and water from the bottom of the pipe. A plate is placed in the middle of the pipe, as
                     shown in Fig.7.9.






                c 
Ascomp AG Switzerland                    285                                  Version 5.7
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