| Author | Nguyen Minh Quang |
| Note | A thesis submitted in partial fulfillment of the requirements for the
degree of Master of Engineering in
Water Engineering and Management, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Abstract | A hydraulic transient, which is a flow condition where the velocity and pressure change
rapidly with time, can collapse a water distribution system if that system is not equipped
with adequate transient protection device(s). The occurrence of transients can introduce
large pressure forces and rapid fluid accelerations into a water distribution system and if
the system is not well protected, it can fail. A hydraulic transient normally occurs when a
flow control component changes status (for example, a valve closing or pump stop), and
this change flows through the system as a pressure wave. Pump stop could be due to
planned stop, power failure or mechanical problem with the pump.
There are many transient analysis methods, but this thesis work employed the method of
characteristics and the finite different method to construct models (using the FORTRAN
language) to calculate and simulate transients in a pipeline. Scenarios of pipe materials and
different control valve devices were applied to the models to study the transient flow. The
valve operating calculation for pressure relief and inlet flow have been newly introduced
into the model.
It was shown that with the smaller Young’s modulus of pipe material, surge pressure is
less, means reduce transients significantly. The water velocity and the frictional coefficient
were seen to be important factors which affect the hydraulic transient, even though both
relate to each other. A high frictional coefficient reduces the velocity and as a results
reduces the transients, and vice versa. Also low frictional coefficients lead to increase in
water velocities and as a result increase in hydraulic transients, and vice versa. Installing
the air release valve, the system can reduce the surge pressure in the condition that the
pipeline can withstand the reduced pressure. |
| Year | 2008 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Babel, Mukand S;Sutat Weesakul; |
| Examination Committee(s) | Tawatchai Tingsanchali;Clemente, Roberto S.; |
| Scholarship Donor(s) | Electricity of Vietnam (EVN); |