Author(s): Uros Karadzic; Anton Bergant
Linked Author(s): Anton Bergant, Uros Karadzic
Keywords: No Keywords
Abstract: This paper presents recent developments in water hammer and column separation experiments conducted at the University of Montenegro. An experimental apparatus has been developed and constructed at the Laboratory for Energetic Processes. The system consists of a high pressure upstream end reservoir, a 54 m long steel pipeline with inner diameter of 18 mm, a fast closing electro-pneumatic valve that induces a transient event and a low pressure downstream end reservoir. Four dynamic pressure transducers have been installed along the pipeline for capturing high frequency pressure changes. In addition, electromagnetic and ultrasonic flow meters as well as two pressure transducers have been installed for evaluation of initial conditions. Pressure in the upstream end reservoir is kept constant during the water hammer event by compressed air. A high precision air pressure regulator is used for control of the initial pressure in the system. Transient cavitation and column separation phenomena have been observed in a number of experimental runs. A comparison between the experimental and numerical results, using the standard quasi-steady skin friction model, shows significant discrepancies in damping and timing of pressure pulses that may be contributed to unsteady friction effects. Future research priorities may be seen in the development of a numerical code for simulation of water hammer phenomena, including effects of transient cavitation and unsteady friction and its verification against results of measurements obtained in the newly developed experimental apparatus.
Year: 2012