A multiple-outlet adaptive boundary condition for Eulerian-Eulerian multiphase numerical simulation

An adaptive algorithm was developed to handle some multiphase situations where outlet information is included in results or multiple inlets/outlets are implemented while only flow rates through inlets/outlets are known. This algorithm includes a first-order expanded Bernoulli equation and a mixed approximation algorithm. The expanded Bernoulli equation offers an initialization value for a concerned object for subsequent approximation processes. The mixed approximation algorithm completes final convergence via iteration and correction. The executed code was successfully compiled into a commercial computational fluid dynamics software. To test the algorithm, a series of corresponding experiments were performed. Three key parameters including the validity of the initialization condition from the expanded equation, convergence efficiency and reliability were evaluated and discussed. The results show that this boundary condition could accomplish the desired functions and maintain errors lower than 15% compared to experimental data, and in less rigorous applications, the error may be approximate to 5%. (C) 2019 Published by Elsevier Ltd.