Air-water Annular Two-phase Flow in a Horizontal Tube : 1st Report, Circumferential Distribution of Film Thicknesses

抄録

Experimental investigation was made into circumferential distribution of thicknesses of liquid film formed on the inner surface of a horizontal tube of 26.0 mm I.D. in which air and water flowed concurrently. Superficial velocities of both phases ranged 10∼50m/s for air and 0.006∼0.40m/s for water. The flow pattern concerned was mainly annular flow. The main results obtained are summarized as follows : (1) circumferential distributions of such film thicknesses as the mean, the maximum and the minimum are empirically formulated ; (2) two methods utilizing needle contact and constant current are compared for the measurement of film thickness, and both results are in satisfactory agreement ; (3) film thickness averaged over the entire circumference of the tube is approximately equal to the local mean film thickness at an angle θ=120°measured from the top of the tube cross section ; (4) the data of pressure drop and hold-up are sufficiently correlated by Lockhart-Martinelli parameters.