Time-spatial measurements of cross-sectional mean liquid holdups along a tube axis were carried out in vertical upward huge wave flow and annular flow. In order to study the characteristics of liquid lumps such as liquid slugs, huge waves and disturbance waves, main wave-veins which were the traces of these liquid lumps on time-spatial liquid holdup maps were determined by an algorithm proposed in this paper. Distinctions between liquid slugs and huge waves were achieved based on the information about cross-sectional profiles obtained using a semi-supermultiple-point-electrode probes. Wave velocities and wave widths were determined by analyzing the wave-veins. Probability distributions of these flow parameters were also investigated. It is clarified that there exist distinct differences in wave velocities and wave widths between huge waves and disturbance waves at superficial gas velocities greater than l5m/s.
