In the present study, a water transmission pipeline under steady conditions is modeled followed by examining the transient flow created by the failure of pumps in the pipeline. This pipeline is 31 km from the water transmission pipeline of Kerman, Iran. The software analysis results were compared with those of a numerical model for a laboratory test to validate transient flow modeling. While transient flows are created by pump failure, various areas of the water transmission pipelines will be affected by the transient waves produced. Long water transmission pipelines, usually large in diameter and flow rate, will pose problems in the negative pressure phase. The negative pressure causes threatening problems like water column separation and cavitation. The results indicated that using equipment like air valves when the pumps fail alone does not have the appropriate efficiency in eliminating the hazards in the water transmission pipelines. More examination showed that installing equipment like water flow feed and hydropneumatic tanks along the pipeline length in the right places prevents the negative pressure created and the pipeline risk significantly reduces.

In this paper, the nonlinear sloshing behavior of a liquid in a partially filled tank is studied using the finite-element method (FEM) based on new spherical Hankel shape functions. The liquid free surface is one of the important parameters in the modeling of the sloshing problems. The main aim of this study is the determination of the free surface location using a new finite-element technique. In this new method, the finite-element method with new shape functions is developed and reformulated. These shape functions are derived using the first and second kind of Bessel functions and have properties such as piecewise continuity. Using these new functions, the number of elements can be reduced, while the accuracy of the results can be increased. The application and accuracy of the proposed method are investigated by several problems related to the sloshing behavior of the liquid. The obtained results indicate that the new method is capable of computing the free surface elevation with a lower number of elements with good accuracy.