An Efficient Accurate Shock-capturing Scheme for Modeling Water Hammer Flows - Advances in Control and Automation of Water Systems - page 94

figure 6.3 Column separations due to close of valve.

In present research data collection process, the main pipeline of water networks
of Rasht city in the north of Iran have been used (Research Field Tests Model). Model
of main pipeline of networks have been selected for the city of Rasht, Guilan prov-
ince (with 1,050,000 population). Research data were collected from the PLC of wa-
ter treatment plant pump stations. Water hammer models of the Rasht city pipeline
guided route selection, conceptual and detailed design of pipeline. The pipeline is
included water treatment plant pump station (in the start of water transmission), 3.595
km of 2*1.200 mm diameter pre-stressed pipes and one 50,000 m 3 reservoir (at the
end of water transmission). All of these parts have been tied into existing water net-
works.

6.2.2 modeling and simulations of Water Hammer
Two fundamental laws apply to steady state, or transient models:

• Conservation of mass—also expressed as the continuity equation, which states
that matter cannot be created or destroyed.
• Conservation of energy—also expressed as the momentum equation, which
states that energy cannot be created or destroyed. The best way to arrive at
sound, physically meaningful conclusions and recommendations is to keep
these principles in mind whenever research has interpreted the results of a hy-
draulic model. Present research has made this easy by tracking the mass inflow
or outflow of air or water at any location. This goal has been achieved by plot-
ting or animating the resulted total energy at any point and time in the system.
Friction factor at steady state was the same as unsteady state [4-6]: