The influence of a small gas addition to the structure of gas-liquid downward flow in a tube

A study of the local structure of the turbulent gas-liquid bubble flow in a tube with an inner diameter of 20 mm was performed by using the electrodiffusion method. A special feature of this research is the relatively small (up to 5% of the volume) quantities of gas added to the flow. To determine the radial distribution of the liquid velocity, its pulsations, and the local void fraction, we used a sensor of the blunt nose type, which simultaneously functioned as an electrochemical sensor and a conductivity sensor. It was shown that adding even small quantities of gas into the flow leads to a change in the liquid velocity profile in comparison with the single phase flow and rearrangement of the turbulent structure of the flow.