Unified presentation and comparison of various formulations of the phase stability and phase equilibrium calculation problems

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21340%2F18%3A00325665" target="_blank" >RIV/68407700:21340/18:00325665 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1016/j.fluid.2018.03.013" target="_blank" >http://dx.doi.org/10.1016/j.fluid.2018.03.013</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.fluid.2018.03.013" target="_blank" >10.1016/j.fluid.2018.03.013</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Unified presentation and comparison of various formulations of the phase stability and phase equilibrium calculation problems

Popis výsledku v původním jazyce

In this paper we present general formulations of the phase-equilibrium and phase-stability problems for multicomponent mixtures and verify that these formulations generalize the problems of phase equilibrium and phase-stability at constant volume, temperature, and mole numbers (VTN-flash), at constant internal energy, volume, and mole numbers (UVN-flash), and at constant pressure, temperature, and mole numbers (PTN-flash). Furthermore, we develop a numerical method for solving the general formulation of phase-equilibrium problems. This algorithm is based on the direct minimization of the objective function with respect to the constraints. The algorithm uses a modified Newton-Raphson method, along with a modified Cholesky decomposition of the Hessian matrix to generate a sequence of states with decreasing values of the objective function. The algorithm was implemented in C++ and using generic programing we have a single, portable solver for all three flash formulations. Properties of the algorithm are shown on phase-equilibria problems of multicomponent mixtures in different specifications and with different levels of difficulty. Complexities and numerical performance of the individual flash formulations are discussed. (C) 2018 Published by Elsevier B.V.

Název v anglickém jazyce

Unified presentation and comparison of various formulations of the phase stability and phase equilibrium calculation problems

Popis výsledku anglicky

In this paper we present general formulations of the phase-equilibrium and phase-stability problems for multicomponent mixtures and verify that these formulations generalize the problems of phase equilibrium and phase-stability at constant volume, temperature, and mole numbers (VTN-flash), at constant internal energy, volume, and mole numbers (UVN-flash), and at constant pressure, temperature, and mole numbers (PTN-flash). Furthermore, we develop a numerical method for solving the general formulation of phase-equilibrium problems. This algorithm is based on the direct minimization of the objective function with respect to the constraints. The algorithm uses a modified Newton-Raphson method, along with a modified Cholesky decomposition of the Hessian matrix to generate a sequence of states with decreasing values of the objective function. The algorithm was implemented in C++ and using generic programing we have a single, portable solver for all three flash formulations. Properties of the algorithm are shown on phase-equilibria problems of multicomponent mixtures in different specifications and with different levels of difficulty. Complexities and numerical performance of the individual flash formulations are discussed. (C) 2018 Published by Elsevier B.V.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10102 - Applied mathematics

Projekt

<a href="/cs/project/GA17-06759S" target="_blank" >GA17-06759S: Vyšetřování podpovrchového proudění s fázovými přechody</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2018

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Fluid Phase Equilibria

ISSN

0378-3812

e-ISSN

1879-0224

Svazek periodika

476

Číslo periodika v rámci svazku

Nov

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

28

Strana od-do

61-88

Kód UT WoS článku

000447551500003

EID výsledku v databázi Scopus

2-s2.0-85052004270