Prediction of the onset of slug flow in nearly horizontal air-water countercurrent flow

The transition from a statified wave to a slug flow has been analyzed considering the mechanistic forces acting on the wave crest in a nearly horizontal air-water countercurrent flow. To verify the results of the analysis, a series of experiments have been performed changing the inclination anlge of the test section. Comparisons of the theoretical predictions with experimental data show a good agreement and the results show that the present model gives similar results of Taitel and Dukler's in the case of inclined pipes. However, at high superficial liquid velocity, the results of present work agree more closely with data than that of Taitel and Dukler's. Also, predictions of the present model gives a very closs agreement with the experimental data for various tube sizes obtained by others