Flow behavior of liquid falling film on a horizontal corrugated tube

Abstract The intertube flow pattern presents droplet, droplet-column, column, column-sheet, and sheet with the increase of flow rate on the falling film flow process outside a horizontal corrugated tube. The film Reynolds number of each flow pattern transition of a horizontal corrugated tube is less than that of a horizontal smooth tube. The corrugated tube surface is more favorable to axial spreading of the liquid film compared with the smooth tube. The droplet or column departure-site spacing is smaller than in a smooth tube. As the intertube spacing of the horizontal corrugated tubes increases, the film Reynolds number of each flow pattern transition and the droplet or column departure-site spacing are increased. Based on the experimental data, a new correlation has been suggested to predict the column departure-site spacing of a horizontal corrugated tube.