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Analiza pojave nestabilnosti kod dvofaznog strujanja u poroznoj sredini

dc.creatorJaćimović, Nenad
dc.creatorHosoda, Takashi
dc.creatorIvetić, Marko
dc.date.accessioned2019-04-19T14:13:57Z
dc.date.available2019-04-19T14:13:57Z
dc.date.issued2009
dc.identifier.issn0350-0519
dc.identifier.urihttp://grafar.grf.bg.ac.rs/handle/123456789/252
dc.description.abstractThe paper deals with modeling of two phase (water-air) flow in coarse porous medium, where, after reaching some air velocity, instability of the flow occurs. Firstly, a linear stability analysis has been conducted for onedimensional macroscopic model, which revealed that capillary forces are a stability factor, while inertial forces promote instability. Utilizing the two most frequently applied constitutive models for capillaritysaturation relation it was found that instability may be expected in materials with representative grain size of 2 mm and greater. In the case of smaller grain size, instability can not occur, regardless of the imposed air flow rate. In addition, the paper presents a newly developed numerical model for the simulation of two phase flow in porous media, with the consideration of complete momentum equations. Applied on the data of reported laboratory experiments the model successfully reproduced the observed instability of the flow.en
dc.description.abstractU radu se modelira dvofazno tečenje vode i vazduha u krupnozrnoj poroznoj sredini gde je, pri određenim brzinama vazduha, osmotrena pojava nestabilnog tečenja. Najpre, sprovedena je linearna analiza stabilnosti zapreminski osrednjenih jednačina, koja je pokazala da osnovni stabilizirajući faktor predstavljaju kapilarne sile, dok inercijalne sile promovišu nestabilnost pri tečenju. Korišćenjem dva najčešće korišćena konstitutivna modela za funkcionalnu zavisnost kapilarnog pritiska i zasićenosti porozne sredine, utvrđeno je se pojava nestabilnosti može očekivati kod materijala reprezentativne krupnoće zrna veće od 2 mm. Kod manje krupnoće, pokazano je da do nestabilnog tečenja ne može da dođe, bez obzira na nametnutu brzinu vazdušne faze. U okviru rada, razvijen je i numerički model za rešavanje dvofaznog tečenja rešavanjem kompletnih dinamičkih jednačina za obe faze (voda i vazduh), a koji je primenjen za simulaciju objavljenih laboratorijskih eksperimenata iz literature. Model uspešno reprodukuje pojavu nestabilnog tečenja.sr
dc.publisherJugoslovensko društvo za odvodnjavanje i navodnjavanje, Beograd
dc.rightsopenAccess
dc.sourceVodoprivreda
dc.subjecttwo phase flowen
dc.subjectporous mediaen
dc.subjectdvofazno strujanjesr
dc.subjectporozna sredinasr
dc.titleInstability analysis of the air-water flow in porous mediumen
dc.titleAnaliza pojave nestabilnosti kod dvofaznog strujanja u poroznoj sredinisr
dc.typeconferenceObject
dc.rights.licenseARR
dc.citation.epage157
dc.citation.issue4-6
dc.citation.other41(4-6): 151-157
dc.citation.rankM51
dc.citation.spage151
dc.citation.volume41
dc.identifier.fulltexthttp://grafar.grf.bg.ac.rs//bitstream/id/3719/250.pdf
dc.identifier.rcubconv_105
dc.type.versionpublishedVersion


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