抄録
Slugging of a stagnant liquid at a V-shaped elbow in a hilly-terrain pipeline is experimentally investigated to obtain information on flow regime and critical conditions of the slugging. According to flow observation using a high-speed camera, the flow is classified into seven flow regimes, i.e. static puddle, wavy puddle, periodic slug flow, periodic semi-slug flow, aperiodic semi-slug flow, film flow and pebble flow. The onset of the slugging is well predicted not by the Mishima-Ishii's model, but by the Wallis parameter used for flooding in a pipe. This means that the slugging at the V-shaped elbow is similar to the flooding caused by interfacial shear stress. An empirical correlation based on a modified Wallis parameter is proposed to represent the effects of inclination angle, pipe diameter and fluid properties on the onset of slugging.
