Modeliranje zadrževalnega časa vode v Tržaškem zalivu : diplomska naloga

Terzić, Elena (author), Žagar, Dušan (mentor), Ličer, Matjaž (comentor)

Z Lagrangevim modelom Nafta3D smo izvedli simulacije zadrževalnega časa vode v Tržaškem zalivu na osnovi hitrostnih polj, pridobljenih z modelom NAPOM. Model Nafta3D smo prilagodili drugačnemu vnosu hitrostnih polj in drugačni začetni porazdelitvi delcev. Račune smo izvedli s hkratnim umerjanjem vertikalnega koeficienta turbulentne difuzije (Dv) za vsako simulacijo posebej s povprečnimi dnevnimi hitrostnimi polji za leto 2012. Razpon možnih zadrževalnih časov za posamezno obdobje računa smo izračunali po metodi drsečega zaporedja intervalov. Določili smo tudi okvirne sezonske vrednosti zadrževalnih časov in območja ustreznih Dv. Zadrževalni čas v obdobjih močnega vetra znaša približno 5 dni, v obdobjih šibkega vetra pa nad 20 dni. Primerjali smo število preostalih delcev v računskem območju v slojih ob gladini in pri dnu in pokazali, da je pri šibkem vetru zadrževalni čas vode v pridnenih slojih veliko daljši kot v slojih ob gladini. Izvedli smo še enostavno statistično analizo in preverili morebitno povezavo med jakostmi vetrnih napetosti in zadrževalnimi časi. Gre za prvi poskus tovrstnega modeliranja v Tržaškem zalivu, zato predstavlja naloga predvsem osnovo za nadaljnje raziskave, hkrati pa smo pokazali tudi pomanjkljivosti modela Nafta3D, ki jih je potrebno odpraviti za izvedbo zanesljivejših simulacij zadrževalnega časa v prihodnje.

• Language: Slovenian
• Keywords: gradbeništvo, zadrževalni čas, vertikalni koeficient turbulentne difuzije, model Nafta3D, vpliv vetra, Tržaški zaliv, severni Jadran
• Work type: Undergraduate thesis
• Typology: 2.11 - Undergraduate Thesis
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Place of publishing: Ljubljana
• Publisher: [E. Terzić]
• Year: 2015
• Number of pages: XI, 53 str.
• PID: 20.500.12556/RUL-32748
• UDC: 004.4:532.5:665(262.3)(043.2)
• COBISS.SI-ID: 6983777
• Publication date in RUL: 10.07.2015

TERZIĆ, Elena, 2015, Modeliranje zadrževalnega časa vode v Tržaškem zalivu : diplomska naloga [online]. Bachelor’s thesis. Ljubljana : E. Terzić. [Accessed 18 April 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=32748

Secondary language

• Language: English
• Title: Modeling residence time of water in the Gulf of Trieste

Abstract

The Langrangian model Nafta3D and the velocity calculated with the NAPOM model were used to compute the residence time of water in the Gulf of Trieste. The Nafta3D model had to be upgraded by adjusting the input of velocity fields and the initial distribution of particles. All simulations required manual calibration of the vertical turbulent diffusivity coefficient (Dv). Daily averaged velocity fields for the entire year 2012 were used in simulations. The range of possible residence times was computed using the moving sequence approach. The approximate seasonal range of residence times was determined together with the corresponding range of Dv. Within the high wind periods the residence time is about 5 days; it exceeds 20 days in low wind periods. The number of residual particles along the water column was determined in order to prove that in low wind conditions the residence time in the surface layers is significantly lower compared to the bottom layers. A simple statistical analysis was performed in order to determine possible relationship between the surface wind stress and the residence time. As the first attempt of residence time modelling in the Gulf of Trieste, the thesis represents a valuable basis for further research. Furthermore, we pointed out the necessary improvements in the Nafta3D model for more accurate computations of the residence time in the future.

• Keywords: graduation thesis, civil engineering, residence time, vertical coefficient of turbulent diffusivity, model Nafta3D, wind impact, Gulf of Trieste, Northern Adriatic