Modelna podobnost in vpliv modelnega merila na prenos rezultatov fizičnega hidravličnega modela na prototip : magistrsko delo

Rodič, Primož (author), Steinman, Franci (mentor)

V magistrski nalogi je obravnavano področje fizičnega hidravličnega modeliranja. Fizični hidravlični modeli so neizogibno podvrženi vplivu modelnega merila zaradi porušenega medsebojnega razmerja sil, ki delujejo na prototipu in na modelu. Ta razmerja so predstavljena v obliki brezdimenzijskih števil. Opisani so zakoni modelne podobnosti in podane omejitve pri uporabi fizičnih hidravličnih modelov. Podane so teoretične osnove prelivanja vode čez preliv. Vpliv modelnega merila je bil analiziran na primeru treh geometrijsko podobnih prelivov v merilih 1:26, 1:50 in 1:100, na katerih so bili izmerjeni tlaki na prelivu, vzdolžni potek prelivne gladine in pretočna sposobnost. Razlike tlakov na prelivu in vzdolžnih potekov gladine so manjše od merilne negotovosti meritev. Pri določitvi pretočnega koeficienta je bila skupaj z meritvami uporabljena tudi teoretična enačba, v kateri so upoštevani ključni parametri. Dominantni vpliv na velikost pretočnega koeficienta ima viskoznost vode, medtem ko je vpliv površinske napetosti praktično povsem zanemarljiv in je bil opazen šele na modelu v merilu 1:100.

• Language: Slovenian
• Keywords: gradbeništvo, magistrska dela, fizični hidravlični model, podobnost, vpliv modelnega merila, prelivi, pretočni koeficient, viskoznost, površinska napetost
• Work type: Master's thesis
• Typology: 2.09 - Master's Thesis
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Place of publishing: Ljubljana
• Publisher: [P. Rodič]
• Year: 2016
• Number of pages: XXVI, 84 str., [20] str. pril.
• PID: 20.500.12556/RUL-88894
• UDC: 532.533(043.3)
• COBISS.SI-ID: 7872353
• Publication date in RUL: 27.01.2017

Secondary language

• Language: English
• Title: Model similarity and the impact of the model scale to transfer the results from the physical hydraulic model to the prototype

Abstract

The master’s thesis is addressed to the area of the physical hydraulic modeling. Physical hydraulic models, or scale models, are inevitably influenced by the so called scale effects due to disturbed ratios of forces acting on the prototype and the model. These ratios are expressed by the nondimensional numbers. General laws of mechanical similarity are presented. Theoretical bases of the weir flow are also presented. Scale effects were analyzed in the case of the three geometrical similar weirs, made in 1:26, 1:50 and 1:100 scales. The measurements of pressures on the weir surfaces and longitudinal water surface courses have shown the measurement uncertainty is greater than their differences. The discharge coefficient was evaluated by the means of measurements and the equation, which takes into account the essential parameters of the scale effects. It has been shown that a higher relative impact of the scale effects is due to viscosity while surface tension is mostly negligible as it was detected only in the smallest model in the 1:100 scale.

• Keywords: civil engineering, master of science thesis, physical hydraulic model, similarity, scale effect, weirs, discharge coefficient, viscosity, surface tension