Rostami Alireza


 Water hammer analysis by perturbation method and cubic-spline interpolations

Student Name

Alireza Rostami



Mohammad Reza Chamani
(Assist. Prof._Civil Engineering Department_Isfahan University of Technology)

Keyvan Asghari
(Assist. Prof._Civil Engineering Department_Isfahan University of Technology)









For many years, the Fix-Grid method of characteristic (MOC) has been used to analyze transient flows in pipeline systems It is noted generally for it's numerical efficiency, computational accuracy, and programming simplicity.

In this thesis, a general assessment of approximate solution of water hammer equations by perturbation method has been accomplished. All interpolation schemes that are used so far have also been applied in the Method Of Characteristics (MOC). In addition, several new cubic-spline interpolation schemes for complete and approximate water hammer equations have been developed.

It is shown that when using complete equations with large time steps, the methods of cubic-spline interpolation, especially the time-line interpolation, resulted in better solutions compared to linear interpolation. Results also indicated that space and time-line interpolations in approximate and complete equations, respectively, achieved better solution among other methods. Considering all factors in choosing the best interpolation method, the space-line cubic-spline method, using approximate form of the equations, reveals the most efficient and practical method of computation.