Water Hammer in a Horizontal Rectangular Conduit Containing Air-Water Two-Phase Slug Flow

Abstract

AbstractThe study of water hammer in air-water, two-phase flows in hydraulic structures such as pressurized pipelines and tunnels, siphons, culverts, and junctions is of great importance for design purposes. Water hammer if combined with a periodic slug flow would lead to severe periodic transient pressure fluctuations inside the conduit. Laboratory experiments have been conducted to investigate water-hammer pressure inside a horizontal rectangular conduit carrying a two-phase, air-water slug flow. Tests were performed in an experimental apparatus comprising a 6.8-m-long transparent pipeline 0.06 m wide and 0.1 m high. By rapidly closing a control gate at the end of the conduit, propagating pressure surges were generated. Transient pressure fluctuations were recorded by means of pressure transducers. Furthermore, a digital camera was used to document flow properties and air-bubble characteristics throughout the pipeline. Pressure measurements along the pipe indicated that two scenarios could be considered...