JOURNAL OF THE FACULTY OF ENGINEERING AND ARCHITECTURE OF GAZI UNIVERSITY, cilt.24, sa.2, ss.359-368, 2009 (SCI-Expanded)
The aim of this study is to search the unsteady flows due to shut-off of the pump. Pressures have been measured at the immediate outlet of the pump. Valve and elbow head losses were determined for different steady state discharges. Thus, the numerical values and empirical expressions for loss coefficients versus velocities were derived. Numerical results were obtained by computer program written in Fortran language using the method of characteristics. In numerical solution, the pump behavior which constitutes the upstream boundary condition is expressed by means of head balance and speed change equations written in terms of dimensionless parameters. An acceptable agreement is observed between theoretical and experimental results. Since the discrepancy between theoretical and experimental results is negligible, one can deduce that the used method and approaches are convenient.