Mathematical Modeling of Hydraulic Transients in Simple Systems - Advances in Control and Automation of Water Systems - page 27

a powerful tool to plan the potential risks to which an installation may be exposed and
developed suitable protection strategies. Their model produced good numerical results
within the accuracy of the used data.
This model was later generalized to include a pumping station fitted with check
valve, delivery valve, and two air vessels. Izquierdo and Iglesias (2005), Ghidaoui,
Mansour, and Zhao (2002) have proposed a two and five-layer eddy viscosity model
for water hammer simulation [3, 4]. Zhao, Ghidaoui, and Godunov have formulated
first- and second-order explicit finite volume (FV) methods of Godunov-type for wa-
ter hammer problems [5, 6]. They compared the performances of FV schemes and
Method of Charecteristics (MOC) schemes with space line interpolation for three test
cases with and without friction. They modeled the wall friction using the formula of
Brunone, Golia, and Greco (1991). The first-order FV Godunov-scheme produced the
same results with MOC using space line interpolation. It was also shown that, for a
given level of accuracy, the second-order Godunov-type scheme requires much less
memory storage and execution time than the first-order Godunov-type scheme. Re-
cently, Kodura and Weinerowska (2005) have investigated the difficulties that may
arise in modeling of water hammer phenomenon [7]. Ghidaoui and Kolyshkin (2001)
have performed linear stability analysis of the base flow velocity profiles for laminar
and turbulent water hammer flows [8]. They found that the main parameters that gov-
ern the stability of the transient flows are the Reynolds number and a dimensionless
time scale. This chapter provides a suitable way for detecting, analysis, and records of
transient flow (down to 5 milliseconds) due to pump pulsation for water transmission
line of Rasht city in the north of Iran. Transient flow has been solved for pipeline in
the range of approximate equations. These approximate equations have been solved by
numerical solutions of the nonlinear Navier-Stokes equations in the MOC.
2.2 mAteriAls And metHods
2.2.1 field and lab tests for disinfection of Water transmission lines
Field Tests: The Field Test was included water treatment plant pump station (in the
start of water transmission line), 3.595 km of 2*1200mm diameter pre-stressed pipes
and one 50,000 m³ reservoir (at the end of water transmission line). All of these parts
have been tied into existing water networks.
Laboratory Model: A scale model have been built to reproduce transients ob-
served in a prototype (real) system, typically for forensic or steam system investiga-
tions. This research Lab. model has recorded flow and pressure data. The model is
calibrated using one set of data and, without changing parameter values. (Figure 2.2)
• Laboratory Model Dateline: The model has been calibrated and final checked
by water hammer Laboratory Models.
• Sub-atmospheric leakage tests performed according to ASTM standards. This
was done to explain repeated pipe breaks. This work led to improved standards
for gasket designs and installation techniques in the province of sub atmospheric
transient pressures which can suck contaminants into the water system [9].