Initiation and Statistical Evolution of Horizontal Slug Flow With a Two-Fluid Model

Abstract

In the present work, the onset and subsequent development of slug flow in horizontal pipes is investigated by solving the transient one-dimensional version of the two-fluid model in a high resolution mesh using a finite volume technique. The methodology (named slug-capturing) was proposed before in the literature and the present work represents a confirmation of its applicability in predicting this very complex flow regime. Further, different configurations are analyzed here and comparisons are performed against different sets of experimental data. Predictions for mean slug variables were in good agreement with experimental data. Additionally, focus is given to the statistical properties of slug flows such as shapes of probability density functions of slug lengths (which were represented by gamma and log-normal distributions) as well as the evolution of the first statistical moments, which were shown to be well reproduced by the methodology.

Simplified 1D Incompressible Two-Fluid Model with Artificial Diffusion for Slug Flow Capturing in Horizontal and Nearly Horizontal Pipes

“…Issa and Kempf [11] suggest to no longer solve the gas momentum equation and to set to zero the gas velocity when the gas volume fraction becomes negligible; however, they keep on solving the gas continuity equation, and when the gas volume fraction rises again above the prescribed threshold, the numerical solution of the momentum balance equation is re-introduced. Later, Nieckele et al [25] followed this approach. Bonizzi et al [26] introduced two thresholds to identify the transition from stratified to slug flow, one to observe when the gas volume fraction becomes small and one to observe the change of the volume fraction of the remaining gas, which must also be small.…”

“…The aforementioned transition criteria were developed for the four-equation two-fluid model [11,25,27,29], the five-equation two-fluid model [28], the six-equation two-fluid model [30] and the multi-field model [26]; as far as we know, no transition method has been developed for the case of a simplified two-fluid model, and thus, we develop here, for the first time, a completely new criterion for the two-equation model, on the basis of the previous literature.…”

Avaliação Da Pressão Dinâmica No Modelo De Dois Fluidos Unidimensional Aplicado Ao Escoamento Anular Vertical

“…A metodologia proposta por Issa & Kempf (2003) vem sendo aplicada com sucesso em diversos trabalhos por seu grupo de pesquisa, envolvendo aplicações específicas, como por exemplo: escoamento em golfadas com consideração do entranhamento de bolhas (Bonizzi, 2003); escoamento trifásico (óleo,água e gás) no regime de golfadas (Bonizzi & Issa, 2003); transição de escoamento estratificado e anular em dutos horizontais (Emamzadeh & Issa, 2013). O grupo de pesquisa da PUC-Rio também vem aplicando com sucesso essa metodologia, com a previsão detalhada dos parâmetros estatísticos das golfadas (Nieckele et al, 2013); analisando escoamento em golfadas com transferência de calor (Simões et al, 2014) e escoamento estratificado e golfadas envolvendoóleos viscosos (Pasqualette et al, 2015), dentre outros.…”

Optimization of the Interfacial Shear Stress and Assessment of Closure Relations for Horizontal Viscous Oil-Gas Flows in the Stratified and Slug Regimes

“…This topic is out of the scope of this work. In their formulation, Bonizzi et al (2009) In their work, Pasqualette et al (2015) used the same Regime Capturing Methodology as Nieckele et al (2013) for simulating isothermal horizontal viscous oil-gas flows. The purpose was to correctly capture the flow pattern transition caused by an increase in the superficial gas velocity for a constant liquid flow rate, starting from a slug flow to stratified wavy flows with large and small interfacial waves.…”

“…With this methodology, the same set of correlations can be used for all the flow patterns, which is in great contrast with the other two approaches. Nevertheless, although very promising and satisfactorily validated for air-water flows (Carneiro et al, 2011;Nieckele et al, 2013;Han & Guo, 2015;Ferrari et al, 2017), this methodology has, with few exceptions, not being much explored for performing 1D…”