الخلاصة:
ABSTRACT
Transportation by pipeline is the means most frequently used to
transport water for their safe and economical properties and also for their
ability to maintain a high quality of life. A pipelines flow condition where
the velocity and pressure change rapidly with time is called hydraulic
transient. It can collapse a water pipeline system if that system is not
equipped with adequate transient protection device(s). A hydraulic transient
normally occurs when a flow control component changes situation (for
example, a pump stopping or valve closing), and this flow changes through
the system as a pressure wave is called water hammer phenomenon. The
water hammer transient is a non-uniform flow which is a change in the
pressure resulting from a sudden change in the flow.
The mathematical model has been verified with several
published data namely (Elbashir and Amoah (2007), Gubashi and Kubba
(2010) and Mansuri et al. (2014)). It is found that the developed
mathematical model agree very well with these previous studies and can rely
on it for simulation a transient water flow in pipes. The developed model was
used to simulate the water transport from region called Five Bridges to Wadi
abi-Naft (within the villages of Clans Neda) in the outskirts of Mandali city,
Diyala governorate, Iraq. The total length of pipeline path is 54km. The
simulation results showed that the pipeline path need three pumping stations
II
in order to transport water to Mandali City. The pipeline used
with diameter is equal to 1200mm. Each
pumping station was simulated separately under transient flow condition.
The required remediation to overcome the water hammer phenomenon is
suggested. A surge tanks with different capacities namely 1700m3, 1530m3
and 1475m3 for first, second and third stage respectively are suggested.
Sensitivity analysis has been performed using several variables
such as p
the diameter of the pipe has a significant effect on the results of water
hammer compared to the effect of both velocity wave and frication factor.
Also, it has been found that the ending section of pipe is the critical zone for
the water hammer effect. In the present study, it has been found that pumps
failure has relatively smaller effect in increasing the negative pressure
compared with the valve closure effect.
