Pipe lines are useful for transporting water for drinking, irrigation and for fire-ing over long distances, this pipe lines are called "Transmission line" and are used to carry conveying raw or treated water from a well field or remote storage (large lake, reservoir, etc.,) facility to a treatment plant and/or distribution storage tank. In water-carrying piping systems, dangerous phenomena may occur. One such phenomenon is water hammer. The water hammer has always been an area of study, which has captivated the minds of researchers due to its complex and challenging phenomena. Modeling the phenomenon in real conditions is extremely difficult. Due to the dimensions of the piping systems, conducting research at real scales is impossible. However, thanks to the development of numerical methods, the study of water hammer and its effects can be performed using simulation programs. This thesis presents value of the equivalent celerity calculated from equations derived using linear analysis of natural vibrations of the system. For implement of the equations, an algorithm in MATLAB has been developed that allows one to easily calculate the equivalent celerity, ce, for N pipelines connected in series with varying diameter, length and material composition. Further in the thesis results of measured dynamic forces and associated displacements recorded on the model caused by transient flow conditions are presented. For measured forces the displacements of the pipe was also calculated by using the oscillation motion equations. Force measurements and displacement analysis were carried out in laboratory on the model of a simple fire protection system equipped with three nozzles. The measurement results and calculations were used to calibrate a mathematical model created using MATLAB software.

Le tubazioni sono utili per il trasporto di acqua potabile, irrigazione e impianti antincendio su lunghe distanze, queste linee sono denominate " Transmission line " e sono utilizzate per trasportare acqua grezza o trattata da un pozzo o da un invaso (lago, serbatoio, diga, ecc.,) ad impianto a un impianto di trattamento e / o serbatoio di stoccaggio. Nei sistemi di tubazioni idriche possono verificarsi fenomeni pericolosi. Uno di questi è il colpo d'ariete. Il colpo d'ariete è sempre stato un fenomeno che ha affascinato le menti dei ricercatori a causa del suo comportamento complesse e stimolante. Modellare il fenomeno in condizioni reali è estremamente difficile. A causa delle dimensioni dei sistemi di tubazioni, è impossibile condurre ricerche su scale reali. Tuttavia, grazie allo sviluppo di metodi numerici, lo studio del colpo d'ariete e dei suoi effetti può essere eseguito utilizzando programmi di simulazione. Questa tesi presenta il valore della celerità equivalente calcolata dalle equazioni derivate dall'analisi lineare delle vibrazioni naturali del sistema. Per l'implementazione delle equazioni, è stato sviluppato un algoritmo in MATLAB che consente di calcolare facilmente la celerità equivalente, ce, per N condotte connesse in serie con diametro, lunghezza e composizione del materiale variabili. Inoltre nella tesi sono presentati i risultati delle forze dinamiche misurate e degli spostamenti associati registrati sul modello causati dalle condizioni di flusso transitorio. Per le forze misurate anche gli spostamenti del tubo sono stati calcolati utilizzando le equazioni del moto di oscillazione. La misurazione delle forza e l'analisi degli spostamenti sono stati eseguiti in laboratorio sul modello di un semplice sistema antincendio dotato di tre ugelli. I risultati della misurazione e i calcoli sono stati utilizzati per calibrare un modello matematico creato utilizzando il software MATLAB.

Influence of celerity and force changes in pressure pipes-phisycal and numerical modelling of transiet flow phenomena / Puntorieri, Pierfabrizio. - (2019 Apr 16).

### Influence of celerity and force changes in pressure pipes-phisycal and numerical modelling of transiet flow phenomena

#### Abstract

Pipe lines are useful for transporting water for drinking, irrigation and for fire-ing over long distances, this pipe lines are called "Transmission line" and are used to carry conveying raw or treated water from a well field or remote storage (large lake, reservoir, etc.,) facility to a treatment plant and/or distribution storage tank. In water-carrying piping systems, dangerous phenomena may occur. One such phenomenon is water hammer. The water hammer has always been an area of study, which has captivated the minds of researchers due to its complex and challenging phenomena. Modeling the phenomenon in real conditions is extremely difficult. Due to the dimensions of the piping systems, conducting research at real scales is impossible. However, thanks to the development of numerical methods, the study of water hammer and its effects can be performed using simulation programs. This thesis presents value of the equivalent celerity calculated from equations derived using linear analysis of natural vibrations of the system. For implement of the equations, an algorithm in MATLAB has been developed that allows one to easily calculate the equivalent celerity, ce, for N pipelines connected in series with varying diameter, length and material composition. Further in the thesis results of measured dynamic forces and associated displacements recorded on the model caused by transient flow conditions are presented. For measured forces the displacements of the pipe was also calculated by using the oscillation motion equations. Force measurements and displacement analysis were carried out in laboratory on the model of a simple fire protection system equipped with three nozzles. The measurement results and calculations were used to calibrate a mathematical model created using MATLAB software.
##### Scheda breve Scheda completa Scheda completa (DC)
16-apr-2019
BARBARO, Giuseppe
ARENA, Felice
Doctoral Thesis
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Utilizza questo identificativo per citare o creare un link a questo documento: `https://hdl.handle.net/20.500.12318/64155`