抄録
Time-varying liquid hold-up was measured for air-water two-phase flow in a 26 mm vertical pipe by means of the constant-current method. The experimental data were collected in froth flow and the transition region between froth and annular flow, where the liquid lumps such as liquid slugs or disturbance waves appeared. A computer-aided-processing was proposed for the determination of flow parameters, i.e., the velocity, frequency, height or length of liquid lump, and the thicknesses of the base and minimum films. It was found that at superficial water velocities lower than 0.7 m/s the liquid lump velocity had a maximum and a minimum with an increasing air velocity ; whereas at higher liquid lump velocities it increased without presenting the maximum and the minimum. It was also suggested that the initiation or termination of froth-annular transition was closely related to the flow conditions under which the flow parameters drastically increased or decreased.
