Entrainment for horizontal annular gas-liquid flow

Measurements of entrainment are presented for air and water flowing in horizontal 2.54 and 5.08 cm pipelines. After the initiation of atomization, entrainment increases with the third power of the gas velocity. At very high gas velocities a fully entrained oendition in reached for which further increases in the gas velocity do not cause a decrease in the flow rate of the wall film. Gas density bas a small effect provided comparisons are made at the same gas velocity rather than at the same mass flowrate. The results are interpreted by asauming that the rate of deposition of droplets on the wall film varies linearly with the concentration of droplets and that the rate of atomization of the wall film varies linearly with its flow rate.