Shape factors inclusion in a one‐dimensional, transient two‐fluid model for stratified and slug flow simulations in pipes
Chapter, Conference object, Peer reviewed
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- SINTEF Proceedings 
In previous works, (Ferrari et al., 2017) have shown that a onedimensional, hyperbolic, transient five equations two-fluid model is able to numerically describe stratified, wavy, and slug flow in horizontal and near-horizontal pipes. Slug statistical characteristics, such as slug velocity, frequency, and length can be numerically predicted with results in good agreement with experimental data and well-known empirical relations. In this model some approximated and simplified assumptions are adopted to describe shear stresses at wall and at phase interface. In this paper, we focus on the possibility to account for the cross sectional flow by including the shape of the velocity profiles, inserting shape factors into the momentum balance equations. Velocity profiles are obtained by the pre-integrated model proposed by (Biberg, 2007) and they are computed at each time step and at each computational cell. Once that the velocity profiles are known, the obtained shape factors are inserted in the numerical resolution. In this way it is possible to recover part of the information lost due to the one-dimensional flow description. Velocity profiles computed in stratified conditions are compared against experimental profiles measured with PIV technique - see (Ayati et al., 2015), showing good agreement. Finally, first results in slug flow configuration are shown.