Utjecaj protoka na intenzitet vodnog udara

master's thesis

• Title (english): The influence of discharge on water hammer intensity
• Author: Ivona Čukman
• Mentor: Goran Lončar (mentor)
• Committee member: Damir Bekić (predsjednik povjerenstva)
• Committee member: Goran Gjetvaj (član povjerenstva)
• Committee member: Goran Lončar (član povjerenstva)
• Granter: University of Zagreb; Faculty of Civil Engineering; (Water Research); Zagreb
• Defense date and country: 2019-07-04, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Civil Engineering; Hydrotechnology

Abstract

U ovom radu provelo se istraživanje vodnog udara. Prvo su navedene teorijske postavke i definicije važnih stavki vodnog udara te je prikazan primjer analitičkog modela. Zatim je provedeno mjerenje u laboratoriju i napravljen fizikalni model. Konačno, na temelju fizikalnog modela napravljen je i hidraulički model u programu ALLIEVI gdje su proračunata stacionarna i tranzicijska stanja. Analitički proračun prirasta tlaka temeljio se na udaru Žukovskom, dok se prirast tlaka u fizikalnom modelu mjerio na tlakomjerima postavljenim na zračnom kotliću i ventilu. Opažanja su provedena vizualno tako da su moguća blaga odstupanja rezultata. Modeliranje u ALLIEVI-u baziralo se na metodi karakteristika te je bilo potrebno kalibrirati zadani hidraulički model. Podešavali su se duljina i promjer cijevi, hrapavost i materijal. Dovodna cijev do zračnog kotlića je od čelika, dok su ostale PE cijevi. Provedena je usporedba rezultata za sve tri metode te se pokazalo kako porastom protoka (brzine) raste i tlak. Najveći prirast tlaka primijećen je za 1.slučaj kada je početno stanje na ventilu iznosilo 1.1 bar, dok je za 2. i 3. slučaj, gdje je početno stanje iznosilo 2 i 3 bara, prirast tlaka bio manji.

Abstract (english)

In this work, a water hammer problem was investigated. First, the theoretical assumptions and definitions of important items of the water hammer are given and an example of an analytical model is presented. Then the measurement was done in the laboratory and a physical model was made. Finally, based on the physical model, a hydraulic model was created in ALLIEVI, where stationary and transitional states were calculated. The analytical calculation of the pressure increase was based on the Žukovsky water hammer, while the pressure increase in the physical model was measured on the pressure gauges mounted on the air chamber and valve. Observations were made visually so that slight discrepancies in the results were possible. The modeling in ALLIEVI was based on the method of characteristics and it was necessary to calibrate the given hydraulic model. The length and diameter of the pipe, the roughness and the material were adjusted. The supply pipe to the air kettle is made of steel, while the other PE pipes. The results of all three methods were compared and the pressure (flow rate) increased. The highest pressure increase was observed for case 1 when the initial state on the valve was 1.1 bar, while for cases 2 and 3, where the initial state was 2 and 3 bars, the pressure increase was lower.

• Keywords: vodni udar; numerički model; fizikalni model
• Keywords (english): water hammer; numerical model; physical model
• Language: croatian
• URN:NBN: urn:nbn:hr:237:952377
• Study programme: Title: Civil Engineering; specializations in: Construction Management, Transportation Engineering, Geotechnical Engineering, Hydraulic Engineering, Structural Engineering, Construction Materials, Theory and Modeling of Structures; Course: Hydraulic Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka građevinarstva (magistar/magistra inženjer/inženjerka građevinarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2019-11-21 11:13:34