International Science and Technology Journal

For decades, water hammer problem in hydropower plants attracts many researchers and engineers for its complexity and importance. In this study, a theoretical investigation of an orifice surge tank is conducted. A mathematical model is derived based on continuity and momentum principles. The system of ordinary differential equations is solved numerically using Runge-Kutta, RK-4, method and compiled by MATLAB. Results reveal that increasing the cross-section area of the surge tank and friction coefficient of the main pipe will lead to a corresponding decrease in water first upsurge levels at the tank and discharge rates as well. The same effect is noticed when orifice friction coefficient is considered. Moreover, the damping effect of orifice friction coefficient on water upsurge levels and discharge rates is more remarkable when compared to friction coefficient of the main pipe wall. Finally, for orifice surge tanks, wave damping time is remarkably small.