G. Dunca - University POLITEHNICA of Bucharest, Romania
R. G. Iovănel - University POLITEHNICA of Bucharest, Romania
D. M. Bucur - University POLITEHNICA of Bucharest, Romania
M. J. Cervantes - Norwegian University of Science and Technology, Trondheim, Norway

The paper presents a new method for in site discharge estimation in pressured pipes. The method consists in using the water hammer equations solved with the method of characteristics with an unsteady friction factor model. The differential pressure head variation measured during a complete valve closure is used to derive the initial flow rate, similarly to the pressure-time (Gibson) method. The method is validated with a numerical experiment, and tested with experimental laboratory measurements. The results show that the proposed method can reduce the discharge estimation error by ۰.۶% compared to the standard pressure-time (Gibson) method for the flow rate investigation.

Pressure measurement, Method of characteristics, Unsteady friction factor, Discharge evaluation, Hydropower