Onset of flooding in a small diameter tube

The main concern of this work is to obtain and investigate the experimental data of the onset of flooding (OSF) for air and water in a small diameter tube. Flooding experiments are carried out in a tube having an inner diameter of 8.75 mm and the length of 1 m at inclination angles of 0, 30, 45, 60° from the vertical. The curves of the OSF are built and shown as a function of the dimensionless superficial velocity. The effects of the inclination angles of the small diameter tubes on the OSF are discussed. The present results are compared with existing limited data reported in literature.