Study of Slug Flow in Horizontal, Inclined, and Vertical Pipes

In the literature several mathematical models have been reported for the slug flow, which uses the concept of the unit slug in common. This concept requires the longitudes of the liquid slug and the Taylor bubble to be known, for the correct evaluation of the terms: phase-wall and interfacial shear stresses, and virtual mass forces. In this work are presented the results of an experimental study of the upward slug flow (in an acrylic pipe with 6 m of length and 0.01905 m of internal diameter). The working fluids are water and air. They were carried out experiments for several angles of tube inclination from horizontal to vertical. The length of liquid slug and Taylor bubble were measured. Also, using voltage signals of two infrared sensors, was determined: (1) The Taylor bubble velocity by means of the cross correlation and (2) The slug frequency when applying the Fourier transform to these obtained data; this information allows to determine the length of liquid slug. It was observed that the Taylor bubble length decreases when increasing the flow of the liquid so much as the angle of inclination, while the Slug length varies with a similar tendency.