Краткое описание

Experiments in a wide range of conditions are carried out at the Harwell LOTUS air-water vertical rig (31.8 mm ID) to provide data set for fully developed flows. Data for pressure drop and (in annular flow) the entrainment fraction are presented and compared with some published correlations. An interesting phenomenon, observed for the first time, is the existence of a region in which pressure gradient increases only slowly with increasing air mass flux in the annular flow regime. Clearly, the data presented here suggested that purely empirical correlations are incapable of predicting the nature of the pressure gradient and none of the correlations are particularly satisfactory for prediction of entrained flow fraction (or liquid film flowrate).