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Computational Analysis of Microplastics Hydrodynamics in Laboratory Experiment
Summary
Researchers conducted computational simulations of microplastic hydrodynamics in an open channel using OpenFOAM with turbulent flow modelling, validating the simulation against laboratory experimental results and examining how particle properties influence settling behaviour.
U ovom diplomskom radu je obrađena tema simuliranja hidrodinamike čestica mikroplastike. U uvodnom dijelu su opisana opća svojstva mikroplastike, te je prikazano matematičko modeliranje čestica. Također je ukratko razmatrana teorija turbulentnog strujanja, te različiti načini numeričkog modeliranja istog, s obzirom da nam je za potrebe provođenja simulacije potrebno prvo odrediti adekvatan turbulentni model. Dan je i opis eksperimenta prema čijim rezultatima kasnije potvrđujemo validnost te preciznost simulacije. Iduća poglavlja opisuju izradu domene i numeričke mreže, te provedbu simulacije stujanja vode u otvorenom kanalu, koju smo vršili radi odabira adekvatnog turbulentnog modela, te je izabran k-ω SST turbulentni model. Simuliranje strujanja vode je također bilo potrebno izvršiti radi dobivanja stacionarnog toka kojeg koristimo pri simuliranju strujanja čestica mikroplastike. Izrada domene i simuliranje su obavljeni u OpenFOAM-u, zbog čega su dane upute za navedeni program. Simuliranje čestica mikroplastike je bilo potrebno obaviti u superračunalnom okruženju, pa se za rješavanje zadatka koristilo superračunalo Bura, čije su tehničke specifikacije i način rada iz tog razloga dani u ovom diplomskom radu. Simulirale su se dvije vrste čestica različitih dimenzija, sferne i nesferne, tj. u ovom slučaju radi uspoređivanja rezultata nesferne čestice su bile kockastog oblika. Ključne veličine koje su se uspoređivale su koeficijenti otpora, te Reynoldsovi brojevi. Pokazalo se da se rezultati simulacije strujanja sfernih čestica izrazito dobro poklapaju s eksperimentalnim rezultatima za iste, dok se za kockaste, tj. nesferne čestice dobivaju znatno lošiji rezultati zbog nedostataka u kodu OpenFOAM-ovog rješavača.
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