Analiza hidrodinamičnih razmer ob zaklopnih zapornicah na bočnem prelivu : doktorska disertacija

Müller, Matej (author), Bajcar, Tom (mentor), Steinman, Franci (co-mentor)

Doktorska disertacija obravnava analizo hidrodinamičnih razmer ob zaklopnih zapornicah na bočnem prelivu, ki se uporabljajo za reguliranje bočnega odliva vode v primeru razbremenjevanja vodotoka ali kanalizacijskega omrežja ali pa za odvzem vode za druge potrebe. Disertacija je bila razdeljena na dva dela: eksperimentalni in numerični del. V sklopu eksperimentalnega dela so bile izvedene meritve pretokov in gladin za 380 variant z različnimi dimenzijami preliva ter različnimi koti odprtja zapornice. Razvita je bila nova enačba za izračun pretočnega koeficienta zaklopne zapornice na bočnem prelivu, ki zajema med drugim tudi vpliv kota odprtja in širine zaklopne zapornice. Opravljene so bile tudi meritve gladin ter meritve hitrostnih polj v različnih horizontalnih in vertikalnih ravninah s t. i. računalniško podprto vizualizacijsko metodo. Iz meritev gladin je bilo možno pokazati, da se kontrakcija curka na robu zapornice spreminja s kotom odprtja, medtem ko so meritve hitrostnih polj pokazale, da ima na pretočnost bočnega preliva z zapornico velik vpliv tudi njena hidrodinamičnost, ki jo v glavnem pogojuje prav položaj zapornice. V sklopu numeričnega dela je bil izdelan 3D numerični model dvofaznega toka, ki uporablja t. i. VOF metodo za določitev medfazne površine. V ta namen je bila uporabljena programska koda OpenFOAM. Obravnavani so bili trije različni modeli turbulence, to so k-ϵ, k-ω SST in LES model turbulence s Smagorinskyjevim podmrežnim modelom. S pomočjo umerjenega 3D numeričnega modela je bil določen tudi vpliv različnih geometrijskih in operativnih parametrov zaklopne zapornice na porazdelitev tlakov po zapornici, ki nastanejo zaradi toka vode. Prav tako so bile izvrednotene rezultante sil zaradi tlakov in torzijski momenti v tečaju zapornice. Dopolnjena pa je bila tudi programska koda OpenFOAM. V sklopu tega je bil izdelan novi solver, poimenovan interWaterFoam, ki omogoča stabilnejše in robustnejše račune z omejevanjem hitrosti v fazi zrak.

• Language: Slovenian
• Keywords: grajeno okolje, gradbeništvo, disertacije, bočni preliv, pretočni koeficient, zaklopna zapornica, VOF, OpenFOAM
• Work type: Doctoral dissertation
• Typology: 2.08 - Doctoral Dissertation
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Place of publishing: Ljubljana
• Publisher: [M. Müller]
• Year: 2016
• Number of pages: XXVI, 141 str., [9] str. pril.
• PID: 20.500.12556/RUL-86838
• UDC: 532.553:627.421(043)
• COBISS.SI-ID: 7828321
• Publication date in RUL: 05.12.2016

Secondary language

• Language: English
• Title: Analysis of hydrodynamic conditions near bottom hinged gates on a side weir : doctoral thesis

Abstract

The doctoral disertation considers the analysis of the hydrodynamic conditions near the bottom-hinged flap gates on a side weir, which are used to regulate the amount of the lateral discharge over the side weir. The disertation is divided into two parts: the experimental and the numerical part. Within the experimental part, discharge and water surface measurements for 380 variants were carried out. A new equation for the discharge coefficient of a bottom-hinged flap gate on a side weir was proposed, which covers the influence of the position and the width of the flap gate on the discharge coefficient. In addition, measurements of water levels near the flap gate and also measurements of the velocity fields were carried out with the computer-aided visualization method. From these measurements, it was possible to show that the contraction of the water jet varies with the gate opening angle. It was also found in which position a flap gate has the most favorable hydrodynamic shape. Within the numerical work, a 3D numerical model of two-phase flow, which uses the so-called VOF method for determining the interface was established. For this purpuse, the software code OpenFOAM was used. Within the numerical modeling three different turbulence models were analysed, these are the k-ε and k-ω SST turbulence model and the LES turbulence model with a Smagorinsky subgrid scale model. With the help of a calibrated 3D numerical model, the influence of different geometric and operational parameters of the flap on the pressure distribution at the gate, caused by the flow of water over the side weir, was analysed. Furthermore, the resultants of the forces and torsion moments in the hinge of the gate were determined on the basis of the results of the numerical model. An update of the OpenFOAM software code was also applied. In this context, a new solver named interWaterFoam was established, which allows more stable and robust calculations with limiting the velocities in the phase of air.

• Keywords: building environment, civil engineering, thesis, side weir, discharge coefficient, flap gate, VOF, OpenFOAM