diplomska naloga
Rok Hamzić (Avtor), Matjaž Četina (Mentor), Sebastjan Bratina (Član komisije za zagovor), Jože Peternelj (Član komisije za zagovor), Mario Krzyk (Komentor)

Povzetek

Dopolnitev modela PCFLOW2D s k-e modelom turbulence za nestalni tok

Ključne besede

gradbeništvo;diplomska dela;UNI;matematični model;PCFLOW2D;k-e model turbulence;model Smagorinsky;metoda končnih volumnov;hibridna shema;nestalni tok;numerična difuzija;PGI Visual Fortran;

Podatki

Jezik: Slovenski jezik
Leto izida:
Izvor: Ljubljana
Tipologija: 2.11 - Diplomsko delo
Organizacija: UL FGG - Fakulteta za gradbeništvo in geodezijo
Založnik: [R. Hamzić]
UDK: 532.5:626/627(043.2)
COBISS: 6064993 Povezava se bo odprla v novem oknu
Št. ogledov: 1954
Št. prenosov: 559
Ocena: 0 (0 glasov)
Metapodatki: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Ostali podatki

Sekundarni jezik: Angleški jezik
Sekundarni naslov: Upgrade of PCFLOW2D model with k-e turbulence model for unsteady flow
Sekundarni povzetek: This thesis presents basic mathematical models used in calculation of turbulent flows worldwide. We upgraded the PCFLOW2D program with the Smagorinsky model and the k-�à turbulence model for unsteady flow. PCFLOW2D is derived from the TEACH program and is written in the Fortran 77 programming language. PCFLOW2D is a two-dimensional depth-averaged model which calculates turbulent flow in open channels. It uses finite volume method of Patankar and Spalding to calculate partial differential equations for unsteady flow. We utilised our upgrades on the mathematical model with hybrid numerical scheme to calculate unsteady flow in a laboratory channel with a side discharge and on a kayaking track on the river So.a near Solkan. Both study cases were calculated using the model of constant effective viscosity, the Smagorinsky model and the k-�à model and the results were compared. Analysis shows that while the new model works, it has some problems with numerical diffusion. It produces physically realistic results, with insufficient length of recirculation, due to increased numerical diffusion. We attempted to solve the problem by condensing the numerical grid, but were unable to entirely remove the numerical diffusion. We also tested an up-to-date Fortran compiler, PGI Visual Fortran, that compared to the current compiler, reduced computational times by 45% on average.
Sekundarne ključne besede: mathematical model;PCFLOW2D;k-ĺ turbulence model;Smagorinsky model;finite volume method;hybrid scheme;unsteady flow;numerical diffusion;PGI Visual Fortran
Vrsta datoteke: application/pdf
Vrsta dela (COBISS): Diplomsko delo
Komentar na gradivo: Univ. v Ljubljani, Fak. za gradbeništvo in geodezijo
Strani: XV, 47 str.
Vrsta dela (ePrints): thesis
Naslov (ePrints): Upgrade of PCFLOW2D model with k-e turbulence model for unsteady flow
Ključne besede (ePrints): matematični model;PCFLOW2D;model turbulence;model Smagorinsky;metoda končnih volumnov;hibridna shema;nestalni tok;numerična difuzija;PGI Visual Fortran
Ključne besede (ePrints, sekundarni jezik): mathematical model;PCFLOW2D;k-ĺ turbulence model;Smagorinsky model;finite volume method;hybrid scheme;unsteady flow;numerical diffusion;PGI Visual Fortran
Povzetek (ePrints): V diplomski nalogi so predstavljeni osnovni matematični modeli in numerične sheme, ki se uporabljajo za izračun turbulentnih tokov pri nas in po svetu. Osredotočili smo se na model Smagorinsky in k-sigma model turbulence za nestalni tok, ki smo ju tudi vgradili v program PCFLOW2D. Program PCFLOW2D je napisan v programskem jeziku Fortran 77 in izhaja iz programa TEACH. PCFLOW2D je dvodimenzionalni matematični model globinsko povprečnega toka s prosto gladino. Za izračun parcialnih diferencialnih enačb nestalnega toka program uporablja metodo končnih volumnov Patankarja in Spaldinga. Posodobitve programa smo preizkusili na primeru laboratorijskega kanala z bo.nim vtokom in primeru tok v kajaka.ki progi na So.i pri Solkanu. Oba primera smo izra.unali z modelom konstantne efektivne viskoznosti, modelom Smagorinsky in k-�Ă modelom turbulence pri hibridni numeri.ni shemi in pri laboratorijskem kanalu primerjali tokovne slike z eksperimetom. Iz analize smo ugotovili, da vgrajeni model turbulence deluje in prika.e fizikalno realne rezultate. Vendar dobimo zaradi pove.ane numeri.ne difuzije v dolo.enih predelih toka premajhno dolžino recirkulacije. Problem smo poskusili rešiti z zgoščevanjem numerične mreže, vendar numerične difuzije nismo uspeli popolnoma odpraviti. Preiskusili smo tudi novejši Fortranov prevajalnik, PGI Visual Fortran in ugotovili, da skrajša računske čase v primerjavi z dosedanjim prevajalnikom v povprečju za 45%.
Povzetek (ePrints, sekundarni jezik): This thesis presents basic mathematical models used in calculation of turbulent flows worldwide. We upgraded the PCFLOW2D program with the Smagorinsky model and the k-�à turbulence model for unsteady flow. PCFLOW2D is derived from the TEACH program and is written in the Fortran 77 programming language. PCFLOW2D is a two-dimensional depth-averaged model which calculates turbulent flow in open channels. It uses finite volume method of Patankar and Spalding to calculate partial differential equations for unsteady flow. We utilised our upgrades on the mathematical model with hybrid numerical scheme to calculate unsteady flow in a laboratory channel with a side discharge and on a kayaking track on the river So.a near Solkan. Both study cases were calculated using the model of constant effective viscosity, the Smagorinsky model and the k-�à model and the results were compared. Analysis shows that while the new model works, it has some problems with numerical diffusion. It produces physically realistic results, with insufficient length of recirculation, due to increased numerical diffusion. We attempted to solve the problem by condensing the numerical grid, but were unable to entirely remove the numerical diffusion. We also tested an up-to-date Fortran compiler, PGI Visual Fortran, that compared to the current compiler, reduced computational times by 45% on average.
Ključne besede (ePrints, sekundarni jezik): mathematical model;PCFLOW2D;k-ĺ turbulence model;Smagorinsky model;finite volume method;hybrid scheme;unsteady flow;numerical diffusion;PGI Visual Fortran
ID: 8312625