Wave characteristics during cocurrent gas-liquid pipe flow

A new non-intrusive video imaging analysis technique (VIMAT) is presented f or the accurate measurement of wave velocity and wave length during co-curr ent gas-liquid flow in horizontal and slightly inclined pipes (-2 degrees < beta < 2 degrees). Wave velocity and wave length measurements with VIMAT a re performed with the systems air/water and air/water-glycerol with superfi cial gas velocities up to 16 m s(-1), including the solitary-waves/atomizat ion regime. It was found that the wave type (smooth, periodic 2D and 3D, so litary) depends on the superficial gas velocity while the wave velocity dep ends on the superficial liquid velocity. A model is introduced to calculate the interfacial wave velocity, which takes the wave type and liquid veloci ty profile into account. A good agreement is found between model and experi mental values. (C) 1999 Elsevier Science Inc. All rights reserved.