Sekundarni jezik: |
Angleški jezik |
Sekundarni naslov: |
Oil-spill trajectory modeling at sea |
Sekundarni povzetek: |
The modelling of spreading and weathering of oil-spills progressed rapidly during the last two decades, supported by fast development of computer technology. Nowadays there are numerous models based on different theories and methods. The trajectory method is one of them. Three models for simulation of oil spreading in the sea (Nafta, Nafta2 and NAFTA3d) have so far been developed at the UL Faculty of Civil and Geodetic Engineering. The models are based on the Lagrangian particle tracking method (PTM). We focused on the trajectory method, which uses statistical principles of contact between oil-particle trajectories and cells of numerical grid. As a result we can calculate the probability of occurrence of oil in each grid-cell. With adequate input data and with a sufficient number of simulated trajectories the model gives us statistically characteristic probabilities for occurrence of oil in any defined area. The original model NAFTA3d was modified and another short programme, which calculates the areas of probabilities for an oil-spill occurrence, was developed. The model was verified on a previously calculated velocity field. Two scenarios of oil-spill in the Gulf of Trieste were simulated, each with three different values for the horizontal coefficient of turbulent diffusion. The results of simulations were found to be coherent, although, because of the relatively short time-range of meteorological and hydrodynamic data, not yet statistically characteristic. |
Sekundarne ključne besede: |
graduation thesis;civil engineering;oil spill;mathematical modelling;transport modelling;trajectory method;Gulf of Trieste; |
Vrsta datoteke: |
application/pdf |
Vrsta dela (COBISS): |
Diplomsko delo/naloga |
Komentar na gradivo: |
Univ. v Ljubljani, Fak. za gradbeništvo in geodezijo |
Strani: |
X, 44 str., 3 str. pril. |
Vrsta dela (ePrints): |
thesis |
Naslov (ePrints): |
Oil - spill trajectorymodelling at sea |
Ključne besede (ePrints): |
razlitje nafte;matematično modeliranje;modeliranje transporta;metoda trajektorij;Tržaški zaliv |
Ključne besede (ePrints, sekundarni jezik): |
oil spill;mathematical modelling;transport modelling;trajectory method;Gulf of Trieste |
Povzetek (ePrints): |
Modeliranje širjenja in razgradnje nafte ob razlitju je v zadnjih dveh desetletjih, s hitrim razvojem računalniške tehnologije, v svetu izjemno napredovalo. Obstajajo številni modeli, ki delujejo na podlagi različnih teorij in metod, med katere sodi tudi metoda trajektorij. Na UL Fakulteti za gradbeništvo in geodezijo so bili do sedaj razviti trije modeli za simuliranje širjenja nafte v morju (Nafta, Nafta2 in NAFTA3d), ki temeljijo na Lagrangeovi metodi sledenja delcev (MSD). V okviru diplomske naloge smo se osredotočili na modeliranje po metodi trajektorij, ki deluje po principu statistike dotika trajektorije naftnega delca in celice numerične mreže. Na ta način dobimo verjetnosti pojava nafte v posamezni celici numerične mreže. Ob ustreznih vhodnih podatkih in z zadostnim številom simuliranih trajektorij nam model poda statistično značilne verjetnosti za pojav nafte na definiranem območju. Novi model temelji na ogrodju NAFTA3d, ki ga je bilo potrebno modificirati, izdelali pa smo še krajši program za izračun območij verjetnosti pojava naftnega madeža. Model smo, na predhodno izračunanih hitrostnih poljih, preverili v dveh scenarijih razlitja nafte v Tržaškem zalivu in pri tem spreminjali horizontalni koeficient turbulentne difuzije. Dobljeni rezultati so ustrezni, vendar zaradi razmeroma kratkotrajnega niza meteoroloških in hidrodinamičnih podatkov še ne statistično značilni. |
Povzetek (ePrints, sekundarni jezik): |
The modelling of spreading and weathering of oil-spills progressed rapidly during the last two decades, supported by fast development of computer technology. Nowadays there are numerous models based on different theories and methods. The trajectory method is one of them. Three models for simulation of oil spreading in the sea (Nafta, Nafta2 and NAFTA3d) have so far been developed at the UL Faculty of Civil and Geodetic Engineering. The models are based on the Lagrangian particle tracking method (PTM). We focused on the trajectory method, which uses statistical principles of contact between oil-particle trajectories and cells of numerical grid. As a result we can calculate the probability of occurrence of oil in each grid-cell. With adequate input data and with a sufficient number of simulated trajectories the model gives us statistically characteristic probabilities for occurrence of oil in any defined area. The original model NAFTA3d was modified and another short programme, which calculates the areas of probabilities for an oil-spill occurrence, was developed. The model was verified on a previously calculated velocity field. Two scenarios of oil-spill in the Gulf of Trieste were simulated, each with three different values for the horizontal coefficient of turbulent diffusion. The results of simulations were found to be coherent, although, because of the relatively short time-range of meteorological and hydrodynamic data, not yet statistically characteristic. |
Ključne besede (ePrints, sekundarni jezik): |
oil spill;mathematical modelling;transport modelling;trajectory method;Gulf of Trieste |
ID: |
8312555 |