On the use of physical boundary conditions for two-phase flow simulations: Integration of control feedback

Abstract

The final publication is available at Elsevier via https://dx.doi.org/10.1016/j.compchemeng.2018.08.012 © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/The sensitivity of two-phase flow simulations using the Euler–Euler model on the inlet boundary conditions (BCs) is studied. Specifically, the physical relevance of Dirichlet uniform inlet velocity BCs is studied which are widely used due their simplicity and the lack of a priori knowledge of the slip velocity between the phases. It is found that flow patterns obtained with the more physically realistic uniform inlet pressure BCs are radically different from the results obtained with Dirichlet inlet velocity BCs, refuting the argument frequently put forward that Dirichlet uniform inlet velocity BCs can be interchangeably used because the terminal slip velocity is reached after a short entrance region. A comparison with experimental data is performed to assess the relevance of the flows obtained numerically. Additionally, a multivariable feedback control method is demonstrated to be ideal for enforcing desired flow rates for simulations using pressure BCs.Natural Sciences and Engineering Research Council of Canad