Bubbly jet impingement in different liquids

Abstract

An experimental setup for the study of bubbly jets collision in microgravity has been designed. On ground preliminary results are presented in order to be compared with those obtained in a near future in low gravity conditions. The opposed-jet configuration is used with the objective to force the collision of two jets, with an impact angle between them that can be changed from 0º (frontal collision) up to 90º. The colliding jets are introduced into a test tank full of liquid by means of two bubble injectors. The bubble generation method is based on the creation of a slug flow inside a junction of capillary tubes of 0.7 mm of diameter. Bubble velocities at the injector outlet and generation frequencies can be controlled by changing the gas and liquid flow rates. We present results on the role played by the impact angle and bubble velocities on the structure of the final jet. A systematic study for different gas and liquid flow rates has been carried out in liquids with different values of surface tension.