Show simple item record

dc.contributor.authorLi, Yiteng
dc.contributor.authorKou, Jisheng
dc.contributor.authorSun, Shuyu
dc.date.accessioned2017-05-31T11:23:11Z
dc.date.available2017-05-31T11:23:11Z
dc.date.issued2017-04-09
dc.identifier.citationLi Y, Kou J, Sun S (2017) Numerical modeling of isothermal compositional grading by convex splitting methods. Journal of Natural Gas Science and Engineering 43: 207–221. Available: http://dx.doi.org/10.1016/j.jngse.2017.03.019.
dc.identifier.issn1875-5100
dc.identifier.doi10.1016/j.jngse.2017.03.019
dc.identifier.urihttp://hdl.handle.net/10754/623875
dc.description.abstractIn this paper, an isothermal compositional grading process is simulated based on convex splitting methods with the Peng-Robinson equation of state. We first present a new form of gravity/chemical equilibrium condition by minimizing the total energy which consists of Helmholtz free energy and gravitational potential energy, and incorporating Lagrange multipliers for mass conservation. The time-independent equilibrium equations are transformed into a system of transient equations as our solution strategy. It is proved our time-marching scheme is unconditionally energy stable by the semi-implicit convex splitting method in which the convex part of Helmholtz free energy and its derivative are treated implicitly and the concave parts are treated explicitly. With relaxation factor controlling Newton iteration, our method is able to converge to a solution with satisfactory accuracy if a good initial estimate of mole compositions is provided. More importantly, it helps us automatically split the unstable single phase into two phases, determine the existence of gas-oil contact (GOC) and locate its position if GOC does exist. A number of numerical examples are presented to show the performance of our method.
dc.description.sponsorshipThis work is supported by the KAUST research fund awarded to the Computational Transport Phenomena Laboratory at KAUST through the grant BAS/1/1351-01-01.
dc.publisherElsevier BV
dc.relation.urlhttp://www.sciencedirect.com/science/article/pii/S1875510017301397
dc.subjectConvex splitting method
dc.subjectHelmholtz free energy
dc.subjectIsothermal compositional grading
dc.subjectSemi-implicit scheme
dc.titleNumerical modeling of isothermal compositional grading by convex splitting methods
dc.typeArticle
dc.contributor.departmentComputational Transport Phenomena Lab
dc.contributor.departmentEarth Science and Engineering Program
dc.contributor.departmentPhysical Science and Engineering (PSE) Division
dc.identifier.journalJournal of Natural Gas Science and Engineering
dc.contributor.institutionSchool of Mathematics and Statistics, Hubei Engineering University, Xiaogan, 432000, , China
kaust.personLi, Yiteng
kaust.personSun, Shuyu
kaust.grant.numberBAS/1/1351-01-01
dc.date.published-online2017-04-09
dc.date.published-print2017-07


This item appears in the following Collection(s)

Show simple item record