Investigation of Waves Interaction in Annular Gas–Liquid Flow Using High-Speed Fluorescent Visualization Technique

High-speed fluorescent visualization complex has been developed for quantitative investigation of the process of interaction of waves on liquid film in annular two-phase flow. Evolution of ripples on disturbance waves surface and disturbance waves coalescence are investigated. It is shown that all the ripples in presence of disturbance waves appear at the base of the back front of disturbance waves and then either decelerate, travel on substrate and are overtaken by the following disturbance wave or accelerate, grow and then disappear at the front of disturbance wave. The disappearance happens due to entrainment of liquid into the core of gas stream. Several scenarios of coalescence of disturbance waves were identified. For disturbance waves with close velocities different types of remote interaction were observed.